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UNITED STATES OF AMERICA. 



the 



Telluric Manual, 



a GUIDE 



TO THE 



Study of Swigert's Lunar Tellurian 



BY 



B?S. LOBDELL, M. S. 



/<^°E^^>s 










Published by 
Central School Supply House. 



CHICAGO, ILL. 



\>s s vX 



Entered according to Act of Congress, in the year 1894, by 

CENTRAL SCHOOL SUPPLY HOUSE, 
In the office of the Librarian of Congress, at Washington, D. C. 



PREFACE. 



This little book is designed to serve as a guide to the 
study of the Tellurian. The language used is simple, and 
the experiments with the Tellurian will enable the pupil to 
readily understand some of the phenomena regarding the 
sun, earth, moon, and the stars that have attracted his atten- 
tion and become a mystery to him. 

The experiments will tend to arouse the curiosity and 
stimulate the observation of the pupil, and will give a new 
meaning to all that he may learn in the study of Geography. 
Latitude will mean more to him than " distance north or 
south of the equator j" and, by .learning the location of 
places, he will know, by induction, facts about them that 
would never occur to him without having seen the demon- 
strations that the Tellurian gives. 

A careful study of places, as outlined in the first chap- 
ters of the Manual, is expected. After this the phenomena 
caused by the rotation of the earth on her axis, the inclina- 
tion of the earth's axis, and the revolution of the earth 
around the sun are to be studied. This will teach the pupil 
the intimate relation that exists between latitude, the length 
of days and nights, and the distribution of light and heat. 
By easy steps he is led to fully understand all that is said 
in the chapter on Climate. 

The study of the Tellurian as herein directed will be 
found to possess much value in acquiring a knowledge of 
Physical Geography. 

Hitherto the globe has been presented as an abstract 
study. The author of the Telluric Manual invites your 
attention to a new treatment of this subject, and begs your 
indulgence. 



CONTENTS. 



CHAPTER 

I, The Tellurian .... 




II. 


The Beginning 




III. 


Directions and Locations . 




IV. 


Meridians and Longitude . 




V. 


Parallels and Latitude 




VI. 


Study of the Globe's Surface 




VII. 


Longitude and Time 




VIII. 


Days and Nights 




IX. 


Yearly Revolution of the Earth 




X. 


Length of Days and Nights . 




XI. 


(1) How to Compute the Length of ) 

Days and Nights > 

(2) Twilight . . . ) 


XII. 


Distribution of Light and Heat 


XIII. 


Climate . . . . 




XIV. 


The Moon .... 




XV. 


The Sun ..... 




XVI. 


Eclipses ..... 




XVII. 


The Calendar .... 
The Appendix .... 





PAGE 



ILLUSTRATIONS. 



Analemma .... 

Compass, the points of 

Crest and Trough of Tides 

Day and Night .... 

Day Hemisphere (in midsummer) 

Eclipse, annular 

Eclipse, partial solar . 

Eclipse, solar .... 

Earth, a sectional view of . 

Figure, illustrating apparent rotation of the Heavens 

Figure, showing orbit of moon and length of earth's shadow 

Figures, showing orbits of sun and moon . 

Figures, showing relative size of earth and moon 

Great Dipper, the, and pole star 

Light and Heat, distribution of . 

Longitude and Latitude ..... 

Lunar Tellurian ...... 

Meridians ........ 

Nodes of the Moon ...... 

Oblique Rays of Sun on Slopes .... 

Parallels ........ 

Polar Projection, showing east and west longitude 
Tellurian, with day and night circles . 

Tides 

Twilight 

Zodiac, etc. ..... . . 



44 Gbe worfts of <3ofc are fair tor naugbt t 
IHnleas our eyes, in seeing, 
See bi&Den in tbe tbing tbe tbougbt 
ftbat animates its being/' 



CHAPTER I. 

THE TELLURIAN. 

To get an accurate idea of the relative extent of 
bodies of land and water, we are obliged to study 
the surface of a globe, for in none of our school text- 
books have we maps drawn to the same scale; and, 
when we say that one country is so many times the 
size of another, it has but little meaning compared 
with the truth as it appeals to the eye when the two 
countries are shown side by side. 

The same is true of latitude. In comparing the 
latitude of New York and London, the pupil has in 
mind a map of the United States and a map of Europe. 
These cities are about the same distance from the top 
of the map, and to say that one is 41 degrees north 
latitude, and the other 52 degrees north latitude, does 
but little in removing the wrong impression that the 
maps have conveyed. 

Placing the meridian circle upon New York, and 

slowly revolving the globe, the bodies of land and 

water, and the cities passing under the circle, will tell 

the story of latitude in a way that the youngest 

(5) 



6 THE TELLURIAN. 

pupil can understand, and that the ablest teacher 
cannot make more easy. 

Comparative Latitude — which means a comparison 
of the length of the days and nights, and of the 
seasons of the year — assists the pupil in classifying 
climate and productions, which in turn tells him 
much about the classes of people that he may expect 
to meet in foreign lands, and so on with the entire 
knowledge that we get by the study of geography, 

It is the province of this book, studied in connec 
tion with the Tellurian, to make the work more a 
matter of experience, and to assist the pupil in observ- 
ing conditions that directly affect every living thing 
upon the face of the earth. Much time will in this 
way be saved, and the study of geography be made 
more attractive. 

Begin the study of the globe by locating the 
different bodies of land and water, continents and 
oceans, islands and seas and lakes, then rivers and 
towns. 

Begin with the nearest city, and locate all of the 
principal cities, telling what nations own them. 

Begin with New York, and locate all seaports. 
Tell how you would make a journey to each, etc. 

We will now study the parts of the Tellurian 
that will be most helpful in gaining a concise 



PARTS OF THE TELLURIAN. 7 

knowledge of the earth's surface, her movements, and 
her relations to the moon and the sun, using the 
names given in the accompanying illustration 




CALENDAR AMD 
SI6NS_0E. ZODIAC 



The Orbit Arm is used to revolve the earth about 
the sun in her yearly revolution. 

The Calendar Index shows the positions of the 
earth in her orbit, by pointing at the names of the 



8 THE TELLURIAN. 

months and the days of the months arranged around 
the base of the Tellurian. 

The Base of the Tellurian represents a belt in the 
Celestial Sphere, called the Zodiac. This belt is 
divided into twelve parts, called Signs, and their names 
will be found in Chapter IX. If you could stand at 
the center of the solar system and watch the earth, 
she would appear to be in one of these signs; and, 
if you could watch the earth for a year, she would 
appear to move from one of these signs to another 
until the entire circuit had been made. The Index 
shows the day and the month. 

The larger globe, or ball, represents the Earth. 
We shall refer to this ball as the "Earth." 

The Sun Segment is a part of a circle represent- 
ing a segment of the Sun, around which the Earth 
revolves. It can be enlarged by drawing out the arms 
at each extremity of the Segment. 

The Sun Pointer, or Needle, is used to represent 
the direct rays of sunlight. It is movable, and can 
be pressed down to the surface of the Earth. 

The Moon Orbit Arm, or Moon Bar, is used to 
carry the Moon around the Earth. 

The smaller ball represents the Moon. The semi- 
circle fastened to the poles of the Moon is used to 



PARTS OF THE TELLURIAN. 9 

show the Circle of the Moon's Illumination, as seen 
from the Earth. 

The movable Semicircle fastened to the poles of 
the Earth, is used in finding the latitude and longi- 
tude of places, and as an astronomical meridian. 
I also call it the Meridian Circle. 

The Day and Night Circle divides the surface of 
the Earth into two equal parts. We call this circle 
the Sunrise and Sunset Circle, the western half being 
the Sunrise Circle, and the eastern half the Sunset 
Circle; and it is sometimes called the Circle of Illumi- 
nation. 

The Twilight Circle is 18 degrees from the Day 
and Night Circle. The portion of the Earth's surface 
between these two circles is called the Twilight Belt. 

The following illustration shows the Tellurian 
ready for any experiment that has reference to the 
midsummer day. You will notice that the calendar 
index points at the 21st of June. By taking hold of 
the orbit arm, and moving it so that the calendar index 
will move toward July, you will get the direction that 
the earth moves in her orbit. By stopping at any 
date you will have the earth in her relative position 
to the sun, ready for any experiment that you may 
wish to try, for any location on her surface. By 
tightening the screw at the north pole, the movable 



10 



THE TELLURIAN. 



meridian will become fixed, and you can rotate the 
earth on her axis to bring the desired locality, or 
place, to any desired position without moving it. 



TWILIGHT CIRCLE 




CALENDAR AMD 
SI&NS_0F_ ZODIAC 



Place the movable meridian over the meridian of New 
York, then, by rotating the earth so that New York 
will move toward the sun pointer, you will get the 
direction that the earth rotates on her axis. 



PARTS OF THE TELLURIAN. 11 

In the study of this Manual, it is expected that 
you will constantly refer to your Tellurian to prove 
the statements made, or to get a clearer idea of what 
is told. 



CHAPTEK II 

THE BEGINNING. 

At the World's Fair, in the Art Gallery, was a 
painting entitled "The Young Astronomer." A 
country lad, sitting on a hillside watching the stars, 
occupied the foreground, while his humble home 
could be seen in the distance, far enough away not 
to disturb the reflections of the young thinker, whose 
face showed his appreciation of the sublimity of the 
scene upon which his gaze was fixed. 

There have been many lads who thus have watched 
the heavens, and wondered why some of the stars 
seemed to move about during the year. The " Milky 
Way " could not have escaped their notice, and they 
have wondered at the meaning of this beautiful path 
in the sky. Sometimes a comet has made its appear- 
ance, and a new field of wonderment has been opened. 
Perhaps the moon has hidden the face of the sun, or 
has gone into the earth's shadow for a short time, and 
the young star-gazer has sought in vain for an explana- 
tion. 

If the heavens could have been viewed with a 

(12) 



"THE YOUNG ASTRONOMER: 1 13 

telescope, new wonders would have been seen on 
every side by these young astronomers. They would 
have seen beautiful white, fleecy clouds here and 
there, that are now thought to be the beginnings of 
solar systems like our own; and, if they could have 
understood the different objects in detail, they would 
have seen worlds in every stage of development, from 
Saturn's rings to our own place of abode. 

But, while now we can definitely know but a few 
things concerning " other worlds than ours," still we 
can learn a great deal about our own that will be of 
interest and profit to us. We know that some rocks 
look as if they had been made in layers; and we 
know, that, if we could take muddy water and let it 
settle, a layer of dirt would be formed. If earth of 
another color should become mixed up with the water, 
and should settle, another layer would be formed at 
the bottom of the water. If these layers should, in 
the course of time, become hardened like stone, they 
would form rocks of different colors and materials, 
just as we have many times seen. From this we can 
tell pretty nearly how rocks that are found in layers 
have been formed. 

Some rocks are glassy, and look as though they had 
been melted, which is probably just what has hap- 
pened to them. From this we infer that the surface 



14 THE BEGINNING. 

of the earth has at one time been at a much higher 
temperature than we can imagine it to have been. 
This carries us one step nearer to the starting point of 
the earth. Where there are very deep mines, it has 
been found that the temperature increases as we 
descend into the solid portions of the earth; and, by 
comparing different places, it has been found that it 
does not vary much from one degree for every fifty 
feet. At this rate of increase of temperature, the 
earth's crust would be at red heat at a depth of 
twelve miles; and, at a depth of one hundred miles, 
the temperature would be high enough to melt most 
of the materials of which it is 
composed. Now, a crust of 
one hundred miles in thickness 
is but a thin layer compared 
to the diameter of the earth, 
which is nearly 8,000 miles; 
and, if you could see a section 
of the earth, it would look something like the 
illustration here given. 

At some points the molten interior comes to the 
surface, being permitted to do so by great cracks in 
the earth's crust. In the course of time materials 
are piled up around these openings, making small 
mountains. Sometimes these openings occur at the 




FORMATION OF THE PLANETS. 15 

tops of mountains, sometimes on level plains, and 
sometimes even in the bed of the ocean. They are 
called volcanoes. 

You will find volcanoes on your Tellurian in 
South America, in Europe, and Asia, — in fact, in 
almost all of the grand divisions of the land and on 
some of the islands. Some islands are nothing more 
or less than volcanoes in the bottom of the ocean, that 
have piled up material around themselves until they 
have become islands. 

It is thought that the earth, and all of the rest of 
the solar system, was at one time a cloud of nebulous 
matter, occupying all the space included in the orbit 
of our most distant planet ; that this matter was 
intensely hot; and that, as it cooled, the particles 
came together, forming an immense ball that was one 
of the stars of the universe. As the mass revolved 
a portion was thrown off, and became what is now 
our most distant planet. As time passed on, another 
portion was thrown off, and formed another planet, 
and so on, until our earth and the remaining planets, 
in like manner, each began its separate course around 
the sun. The earth, in time, lost a portion of her 
matter, and from this the moon was formed, and 
began her revolution around the earth. 

Just how the earth happened to get into the 



16 THE BEGINNING. 

position that she now occupies, no one can tell ; but 
we know, that, if her position had been different, her 
conditions would also have been different from those 
that now exist, as you will see by the study of the 
following chapters in connection with your Tellurian, 
which represents the position of the earth in her 
relation to the sun, and is so arranged as to give 
you her movements as she performs her daily and 
yearly revolutions. 

You will be able to see just how it happens that 
the days and nights are not always of the same length, 
and to see that they always would*, have been of the 
same length if the earth's axis had not been inclined 
toward the sun. 

But before we attempt to study all the relations of 
the earth to the sun and the moon, we must learn 
something of the earth's surface; and ; the first thing 
to do is to learn the directions and the locations of 
all the most important places on the globe. This we 
will do in the next chapter. 



CHAPTER III. 

DIRECTIONS AND LOCATIONS. 

There are a few points on the Tellurian that I 
wish you to learn, so that you can refer to them 
readily, for you will want to use them more or less 
in every lesson that you have to study w T ith reference 
to locations and directions. The first two are the 
North and South Pole. 

If you rotate the earth, you will notice that the 
cities near your own home will move around in a 
circle, and return to the point of starting. This they 
actually do once in twenty-four hours; and, if they 
did not, we would not have days and nights alter- 
nating with each other, but it would either be day or 
night all the time. The earth always rotates from 
the west toward the east ; and, if you will place the 
earth so that your nearest city will be under the 
sunrise circle, and rotate it toward the sunset circle, 
it will move in an easterly direction, and it will be 
day to that city, until it reaches the sunset circle. 
If you continue the rotation in the same direction till 
the city reaches the sunrise circle again, it will be 

(17) 



18 DIRECTIONS AND LOCATIONS. 

back at the starting point. While you are passing 
from the sunset circle to the sunrise circle, it will be 
night, and during this time the earth will still be 
revolving in an easterly direction, the same as during 
the day. It never revolves in any other direction. 
The opposite direction is west. 

We started to learn how to find the north and the 
south pole on the Tellurian ; but I wished to tell you 
how to find east and west first, because direction is 
determined by the earth's rotation. If you will find 
Greenland, and rotate the earth, you will notice that it 
makes a much smaller circle than your city did, for 
Greenland is farther north than your city, and, the 
farther north you go, the smaller the circles will 
become, until you reach their center, which is called 
the North Pole. All places that are between you 
and the north pole are north of you, and, if they are 
not in a direct line, they may be east or west of 
north from you. 

If you go toward the equator from your nearest 
city, you will be going south. After crossing the 
equator, you will notice that, as you rotate the earth 
and watch the places during one revolution, the 
circles will get smaller the farther south you go till 
you come to their center, or the South Pole. All 
places in this direction will be south from you, and, 



CARDINAL POINTS. VJ 

if not in a direct line, they will be east or west of 
south from you. A line passing through the north 
and south pole, and also through the center of thu 
earth, is called the earth's Axis, and the earth rotates 
upon this axis the same as a wheel does upon its axle. 
The rotation of the earth, then, determines the 
location of these two points. 

The east, the direction of the rising sun, and the 
west, the direction of the setting sun, are probably the 
first cardinal points that were made use of by primitive 
man. They were used, without doubt, long before 
north and south were thought of. Probably men 
noticed that a certain star retained almost the same 
position in the heavens during each night in the year, 
and this afforded another reliable point for direction. 
All of the other stars seem to revolve around the star 
which is called the North Star. 

This method of finding north and south, also 
shows you where the extremities of the earth's axis 
are, which are called poles, from a word that means 
a " hinge," a "pivot," or an "axis." So North Pole 
really means that end of the earth's axis that is 
toward the Pole Star. You can easily find the Pole 
Star, or North Star, on some clear night, if you ^vill 
first find the "Great Dipper," and then look in the 
direction of the line in the cut below, which gives its 



20 DIRECTIONS AND LOCATIONS. 

position in the early evening of the 2 2d of September, 
or about that date. 



*c 



N 






\ 



W- 



4 

t 



-cf'b 



The Dipper lies with its handle a little above the 
bowl and pointing to the west. A line drawn 
through the two easternmost stars, a and b y will pass 
near the Pole Star, c. Two of the stars in the 
handle, and the star a in the bowl are much brighter 
than the other stars, and the Pole Star, or North 
Star, is brighter than any of the surrounding stars. 
If the axis of the earth could be extended to the 
heavens, it would pass near this star, and it is a 
strange fact that the Magnetic Needle indicates the 
same direction. 

After the discovery of the properties of the load- 
stone, the invention of the Compass became possible, 
and all points of direction could now be determined 
without dependence upon the rising sun, the setting 
sun, or the North Star. Sailors were no longer 
obliged to wait for clear weather to find m what 



THE MAGNETIC NEEDLE. 



21 



direction they were sailing, and became more venture- 
some, till they were at last able to cross the ocean 
without fear of losing their way, and to find distant 
points without being obliged to coast along the shore 
till they reached them. The Magnetic Needle always 
points toward the Magnetic Pole, which is near the 
North Pole, so near that it is called north, and all 
points of the compass are reckoned from the Magnetic 
Pole. 

The following figure will give the principal points 
of direction, which you may use in giving the 
locations asked for in the last of this chapter. 

N 




The point between N. and N. E. is marked N. N. E., 



22 DIRECTIONS AND LOCATIONS. 

and is read North Northeast ; and between N. E, and 
E. is read East Northeast, etc. You will be able 
to read the other points opposite to these. 

The other two points that I wish you to find are 
on the equator. One of them is where the line running 
north and south through London crosses the equator. 
It is marked with a zero. If you follow the equator 
just half way around the earth, you will find the other 
point. This is marked 180°. It is directly opposite 
the zero point. Places that are the direct opposites 
of each other on the earth's surface are called anti- 
podes. This name is also applied to the people who 
live in the antipodes. Can you tell who are our 
antipodes ? 

These two points, with the first two mentioned, 
are important because they locate the principal lines 
that are used in giving the exact locations of all 
places on the earth. These locations are spoken of 
as the Latitude and the Longitude of places. 

We sometimes speak of Oriental countries, mean- 
ing the countries of Eastern Asia. The East is 
sometimes called the Orient; but, when it is so called, 
the countries are referred to instead of the direction. 
When we speak of the East in this country, we 
usually refer to the New England States, and some- 
times we refer to the Southern States as the South, 



DIRECTIONS AND LOCATIONS. 23 

and the Western States as the West; but, when we 
give the location of a place by giving directions, we 
usually select several well-known places, generally 
important cities, and tell in what direction it is from 
them. 

Small islands, places at sea, and distant places are 
located by giving their latitude and longitude. 

Direction has reference to the earth's surface only. 
We cannot say that the sun, the moon, or the stars 
are north, south, east, or w x est of each other or of 
the earth; but, when we refer to them, we compare 
their location with our own position and some other 
place on the earth's surface that is in the same 
direction. If we see the sun while looking southward, 
we say that the sun is south of us; and, if, in the 
early morning, we should look north of east and see 
the sun, we would say that the sun is farther north 
than we are; but we know that the sun can never 
get farther north than the summer solstice, which is 
about 23^ degrees north of the equator, and is farther 
south than the boundary line of the United States. 
It seems strange that the sun can shine into our 
north window when it first rises on a midsummer's 
day, and still be no farther north* than Havana, 
Cuba. 

* Notice that the latitude of Havana is 23K° north. 



24 DIRECTIONS AND LOCATIONS. 

In the study of the Tellurian, you will see why 
this is true; but there are a number of things to learn 
before investigating this point, and we will begin by 
studying the boundaries of some important countries 
on the surface of the globe. 

We give the boundaries of any country, state, or 
body of water, by naming all the other countries, 
states, or bodies of water that touch it ; and, in doing 
this, we usually begin at the north, then take the east, 
then the south, and then the west, naming all bodies 
of land or water that are contiguous. By giving the 
boundaries, we locate large tracts of land or water. 

The following places will be used a number of 
times to illustrate experiments that will be made with 
the Tellurian, and it will be necessary that you should 
know just where they are. Locate them. 

Karmakuli, St. Petersburg, Berlin, London (Green- 
wich is a part of this city, and is the location of the 
world's observatory, and the center of astronomical 
calculations), Chicago, New Orleans, Seattle, Quito, 
Valdivia, Wellington^ the Antipodes Islands, the 
island near Enderby Land. 

Mention five points for the class to locate. 



LOCATION OF PLACES. 25 

QTJESTIOU8. 

Q. What is the location of Cuba? 

A. Cuba is north of the most western portion of South America, 
east and a little north of Yucatan, and south of Florida. 

Q. What are its boundaries? 

A. It is surrounded by the waters of the Atlantic Ocean. The 
waters on the north are called the Florida Channel and the old 
Bahama Channel; on the < ast, the old Bahama Channel; on the south, 
the Windward Passage and Caribbean Sea; on the west, the Channel 
of Yucatan. 

Locate England, and give its boundaries. Where is New Guinea? 
Give the boundaries of Australia. Locate Borneo, and give its bound- 
aries. What are the boundaries of the United States? What are the 
boundaries of Europe? Locate Iceland, Hawaii, New Zealand, Tas- 
mania, Sardinia, Grahanrs Land, Island of Ceylon. 

Give the boundaries of Asia, South America, Greenland, India, 
Nova Zembla, Russia, Germany, Ecuador, Chili, and Enderby Land. 

What are the points of the compass mentioned in this chapter? 

W T hy are east and west given first? 

What was the next point that was probably used? And what 
locates it? 

What else have we that locates this same direction? 

Do the stars of the Great Dipper seem to stand still? 

What star do they help locate? 

Tell how it is done. 

What is the property of the loadstone that is mentioned? 

What benefit comes from the loadstone? 

What is the Orient? 

How far north does the sun go? 

Are we farther north than this? 

Does the sun ever shine into the north window in this latitude? 

Tell how we give the boundaries of any country. 



CHAPTER IV. 



MEKIDIANS AND LONGITUDE. 



North Pole. 



West. 




East. 



South Pole. 



In the last lesson, we studied directions and 
locations; but, in giving the location of places, we 
were obliged to refer to some place near the locality 
that we were studying, and this place might not 
always be well known, even though it were important. 

(26) 



IMAGINARY LINES. 27 

There is another way of locating that does not 
require the directions to be given, neither does it 
refer to any other place on the earth's surface. It is 
the method employed by sailors, and it refers to 
imaginary lines running north and south, and east 
and west, around the globe. They locate the place 
to which they refer, at their intersection; and then, 
by naming and numbering these lines, one may know 
exactly where the point is without regard to any 
other place. We will see if we can learn to locate 
places by this method also. 

You will notice, on the surface of the globe, the 
two sets of lines that I have mentioned, and that they 
cross each other at right angles. One set runs north 
and south, and the other east and west. While but 
few of them are represented on the surface of the 
globe, still every place has these lines running 
through it, and they help give its exact location. 
These lines go clear around the earth, and form 
circles, which are divided into 360 parts, called 
degrees. Each degree is divided into 60 parts, called 
minutes (of distance), and these minutes are again 
divided into 60 parts, called seconds. One degree of 
a great circle is a little less than 70 miles, so one 



23 MERIDIANS AND LONGITUDE. 

minute would be less than one and one-sixth miles,* 
and a second is less than one-fiftieth of a mile. 
So, by locating by means of degrees, minutes, and 
seconds, you get within less than one-fiftieth of a 
mile of the exact location; but, in the study of the 
globe, we will use only degrees and minutes in 
locating. 

The set of lines that run north and south are called 
Meridians, and all meridians pass through the poles. 
If you put your fingers on the surface of the globe, 
and rotate it to the right (east), these meridians will 
pass under the needle that points toward the center of 
the earth; and, since this needle represents the direct 
rays of the sun, all places passing under it will have 
direct sunlight, — that is, the sun will be directly over 
them. When any point of a meridian is under the 
direct rays of the sun, all points on that meridian will 
have the noon hour. It is from the noon meridian 
that we begin to reckon the time of any place, and 
we say that all places on the noon meridian have 
12 o'clock m. (M. is an abbreviation for Meridies.} 

* The value of a single degree of longitude on the equator is 
equal to about 69J miles. 

At latitude 45° it is equal to about 49 miles 



u 


60° 


tt 


ti 


it 


35 


u 


it 


80° 


a 


« 


it 


12 


a 


it 


90° 


a 


it 


it 





a 



HOUR-CIRCLES. 29 

Before we study the meridians in their relation to 
longitude, we will examine into their relation to time, 
for longitude is often determined by time. As I said 
above, all places have meridians, but not all of the 
meridians are represented on the globe. Only 24 of 
them are marked, and for convenience I shall call 
them Hour- Circles* It requires 24 hours for the 
earth to make one revolution on her axis; and, if you 
divide 360 degrees into 24 equal parts, there will 
be 15 degrees in each part; so a difference of one 
hour in time will represent 15 degrees in distance, 
and the meridians that are given on the globe are 
15 degrees apart, hence they have been given the 
name of u hour-circles/' 

These hour-circles on the globe always bear the 
same relation to each other, being geographical lines, 
located with reference to a line passing from the 
north pole to the south pole through Greenwich, 
England, and do not change their position with 
reference to places on the earth's surface; but, with 



* "Hour-circles'' is the name given to meridians that are 15 degrees 
apart on the Celestial Sphere, counting from the meridian of the sun, 
which is called the Noon Meridian. When we use the meridians on 
the globe for the purpose of estimating time, we take into consideration 
their distance apart only, disregarding the fact that the earth is in 
motion and that all of the meridians revolve with the earth. 



30 MERIDIANS AND LONGITUDE. 

reference to the direct rays of the sun, they move 
east at the rate of 15 degrees for each hour. 

It will be 11 o'clock a. m, {Ante Meridiem) at 
all places on the first hour-circle west of the noon 
meridian, and 10 a. m. at all places on the second 
hour-circle west of the noon meridian. What will be 
the time at all places on the third hour-circle west 
of the noon meridian? 

It is 1 o'clock at all places on the first hour- 
circle east of the one at which the needle points, 
and 2 o'clock at all places on the second east. What 
time is it at all places on the third hour-circle east 
of the one at which the needle points ? Rotate your 
globe so that the needle will point to the zero 
meridian. 

If you will look at England on the globe, you 
can find a city called London, with a meridian 
passing through it. This meridian is called the Zero 
Meridian, and, if you will follow this line down to 
the equator, you will find it numbered with a cipher. 
This is the meridian from which we reckon the 
position of distant places on the earth's surface. If 
you go east or west along the equator, you will find 
that the next meridian given, is marked 15, and the 
next 30. What will the next be marked ? 

If it is 12 o'clock at all places on the zero meridian, 



LONGITUDE. 31 

what time will it be on the meridian 15 degrees 
west? What time on the meridian 30 degrees west? 
What time on the next hour-circle still farther west ? 

When we reckon the distance of any meridian 
east or west of the zero meridian, we call it finding 
its longitude; and, when we say that a place is 15 
degrees west longitude, we rjiean that it is on the next 
hour-circle west of the zero meridian, and the clock 
will tell you that it is an hour earlier at all places 
on that meridian.* Can you tell what the longitude 
of the second hour-circle from this is? How many 
hours earlier is it on that hour-circle? 

Follow the equator west, and see what is the 
greatest number of degrees any hour-circle has. All 
places between this meridian and the zero meridian 
are in west longitude. Find New York, and tell me 
in what longitude it is. In what longitude is San 
Francisco ? 

If you start at the zero meridian and go east to 
the first hour-circle, you will have gone over 15 
degrees of east longitude. How many degrees of east 
longitude will it be when you reach the second hour- 
circle? What is the greatest number of degrees of 
east longitude that you can go? 

* Remember, that, when we are talking about time, the 24 meridians 
shown on the globe are spoken of as "hour-circles." 



32 MERIDIANS AND LONGITUDE. 

If you can go to the next hour-circle beyond this, 
what longitude will it be? If you start at the zero 
meridian, and go east clear around the earth, what 
longitudes will you pass through ? 

In the last lesson we told you that the great circles 
divided the earth into two equal parts. We call each 
of these parts a Hemisphere, a word that means half 
of a sphere or globe. All of the meridians and the 
equator are Great Circles, and you can draw a great 
circle through any place if you will make it divide 
the earth into two equal portions. The equator 
divides the earth into a Northern and a Southern 
Hemisphere, and a great circle drawn through the 
20th degree of west longitude and the 160th degree of 
east longitude, divides the earth into an Eastern and a 
Western Hemisphere. You see that they correspond 
nearly to east and west longitude. While all of 
Europe is in the eastern hemisphere, it is not all in 
east longitude, but a small portion of it is in west 
longitude. While the old geographers wished to 
reckon longitude from Greenwich, they thought it 
would be better to have all of the Eastern Continents 
in the eastern hemisphere, and this is probably the 
reason why they took the meridian of 20° as the divid- 



SIGNS. » 33 

ing line. In studying the globe, it will be necessary 
for you to know the following table for the measure 
of circles : 

60 seconds make 1 minute. 
60 minutes " 1 degree. 
360 degrees " 1 circle. 

The Circle is sometimes divided into 12 parts 
called Signs. 

The equator is divided into degrees; and, since 
there are 15 of these degrees between each of the 
hour-circles, each of these degrees is equal to four 
minutes of time, and half of a degree is equal to two 
minutes. 

You can use the meridian circle to determine the 
number of the meridian that passes through any place, 
by rotating the earth so that the place will come 
under the meridian circle, and then, after seeing at 
what point it crosses the equator, counting the 
degrees to the first hour-circle east, if it is in west 
longitude, and the first hour-circle west, if it is in ea-t 
longitude, and adding them to the number of that 
hour-circle. By practice you can divide the degrees 
into halves and quarters. 



CHAPTER V. 



PARALLELS AND LATITUDE. 




In the last chapter, I told you about the meridians, 
and said that the twenty-four shown on the globe 
were also called hour-circles. I told you that all 
places do not have the same time at the same moment, 
but that, when it is noon at one place, it is earlier at 
all places west of it, and later at all places east of it. 

(34) 



PARALLELS. 35 

I also told you that there were two sets of lines on 
your Tellurian, and gave you the use of one of them, 
the meridians. 

I will now tell you about the other, which you 
will be able to understand better by studying the 
foregoing figure. When we refer to distant places, 
we need to tell more than their longitude to locate 
them, and the lines I am going to tell you about in 
this lesson are used for that purpose. These lines 
go around the earth in the same direction that the 
equator does. They are called Parallels. All places 
on the same parallel are at the same distance from 
the equator. 

Every place has a parallel passing through it, 
but all of the parallels are not represented on the 
Tellurian. Those given are ten degrees apart. In 
the figure at the beginning of this chapter, I have 
given only five parallels; but they are the most 
important on the earth's surface, for they do more 
than to help locate places. One of them, the Equator, 
is used as the basis of reckoning for all of the 
others; two of them, the Tropics, mark the limit 
of the sun's apparent movement north and south; 
and the remaining two, the Polar Circles, mark the 
largest area that remains, at any time during the 
year, in the day or night hemisphere for twenty-four 



36 PARALLELS AND LATITUDE. 

hours or more. But this use of these lines will not 
be discussed in this chapter. 

The parallels given are numbered ; and, if you will 
find the 180th meridian, and go north or south of the 
equator, you will find these numbers, and they will 
tell you the number of degrees that the parallel is 
north or south of the equator. We call this finding 
their Latitude; and places north or south of the 
equator are said to be in North or South Latitude, 
and the equator, which is marked zero, is the dividing 
line. 

The meridian circle on your Tellurian, is divided 
into degrees, and it is especially intended to be used 
in finding the latitude of any place. It has the advan- 
tage of remaining stationary while you rotate the 
earth so as to bring any place under it, and you can 
easily note the degree under which it passes ; at the 
same time, by looking at the equator where the 
meridian circle crosses it, you can also determine the 
longitude of the place. 

I find that the parallel of 20 degrees north latitude 
passes through the Sandwich Islands, and so we 
say, in locating them, that they are 20 degrees north 
latitude. By looking at the equator to see where the 
meridian circle crosses it, I find that they are 155 
degrees west longitude, 



LATITUDE. 37 

Tell what countries the parallel of 40° north lati- 
tude passes through. What two large cities in the 
United States are near this parallel? Locate them. 

If you go south of the equator, you would be in 
south latitude. Rio de Janeiro is about 23° south 
latitude. Can you find it? What is its longitude? 

What states in the United States have the same 
latitude as Morocco in Africa? Can you give the 
latitude and the longitude of the capital of the 
United States? In what latitude is Patagonia? 
Argentine Reuublic? What states in the United 
States are the same number of degrees distant from 
the equator as the Argentine Republic? In what 
latitude are they? 

There are several things that affect the climate, 
but latitude is the most important. As a rule, the 
farther you go from the equator the colder it gets. 
This is one reason why we want to know the latitude 
of places, but there are a number of other reasons 
why we should study latitude. You will learn, in 
another lesson, why the days are longer in summer 
than they are in winter ; but you must understand all 
about latitude first. 

If you really understand all that I have said 
above, you can ask five questions about the latitude 
and longitude of some prominent places on the earth's 



SB PARALLELS AND LATITUDE. 

surface, for your classmates to answer. If you cannot 
ask these questions and answer them without help, 
go over this chapter again, and then see if you can 
do it. 



QUESTIONS OUST CHAPTERS ITT. J^ISTID "V. 

How many ways are there for locating places? 

Which do you think is best? Why? 

What are the straight lines on the globe called? 

Are they really straight lines? 

Into how many parts are they divided? What are the parts called? 

About how many miles long is one of these parts? 

About how many miles west of London is Philadelphia? 

How far apart are the hour-circles? 

Into how many parts must you divide an hour to tell the number 
of minutes that a degree is equal to? 

In what direction from you is it earlier? Later? How many degrees 
from you is it two hours earlier? Three hours later? 

Into what do the great circles divide the earth? 

What is longitude? And what is its use? What is latitude? And 
what is its use? Does it have any other? 

What is the use of the meridian circle that is on your Tellurian? 

What places have parallels and meridians running through them? 

What are the principal meridians? What are their uses? 

Give some of the reasons why you should study latitude? 

Which is the more important, a knowledge of latitude or of longi- 
tude? Why? 

What is necessary to give in locating a place by means of lines? 



CHAPTER VI. 

STUDY OF THE GLOBUS SURFACE. 




Above I have given you a figure that, I hope, 
will be of assistance in showing you how to use 
the Tellurian in the study of this lesson, and in the 
lessons that follow. 

On the Tellurian is a movable meridian circle, 

(39) 



40 THE GLOBE'S SURFACE. 

fastened at the poles of the globe. It has a set- screw 
at the north pole, so that you can fasten the meridian 
circle at any point that you choose, a very desirable 
thing to do when you are studying comparative 
latitude, or, as in the following lessons, in the study 
of time. You will notice that the meridians shown 
on the figure are an hour and a half apart, while 
those on your Tellurian are only one hour apart. I 
have numbered them on the equator, but the numbers 
that I have given the parallels are not the same as on 
the Tellurian. When they are numbered at all, they 
are numbered on the 180th meridian; but, on the 
Tellurian, it is not necessary to number them on the 
globe surface, for their numbers will be found on the 
meridian circle, which can be moved around the globe 
to any point, and fastened with the set- screw, or you 
can fasten it, and then rotate the globe till any point 
comes under the circle. By fixing the circle, and 
rotating the earth, you can easily tell all of the places 
that are in the same latitude, because they will pass 
under the same point on the circle. 

The letter A in the figure is at about the location 
of the Sandwich Islands, and, in giving their location, 
you would say that they are exactly south of Alaska 
and west of Mexico; but, to be more exact, you would 
say that they are 155 degrees west longitude, and 20 



OCEAN CURRENTS. 41 

degrees north latitude. Look it up and see if this is 
correct. You may be able to get it more exact than 
I have given it. 

You will notice, on the surface of the globe, 
another set of lines that have not been mentioned, 
curving here and there through the oceans. They 
represent the Ocean Currents, and they are colored 
red to represent warm, and blue to represent cold 
currents of water which move continuously in the 
same direction. The names of the most important are 
given. These currents need to be studied because of 
their effect on climate; and, besides, they help deter- 
mine ocean routes in navigation, especially for sailing 
vessels. In locating islands, it will be well to tell if 
they are in cold or warm currents of water. 

I have selected the following points, on account of 
their favorable location, for comparison of length of 
days and nights, twilights and climate; viz., Karma- 
kuli (Nova Zembla), St. Petersburg, Berlin, London 
(Greenwich is practically a part of London), Chicago, 
New Orleans, Seattle, Valdivia (Chili), Wellington 
(New Zealand), Antipodes Islands and Enderby 
Land. When I speak of Enderby Land, I shall refer 
to the island located near the point where the meri- 
dian of 60° east longitude crosses the antarctic circle. 



42 THE GLOBE'S SURFACE. 

Locate the above by giving latitude and longitude, using the 
meridian circle in determining both. Of course you can tell whether it 
is in north or south latitude, and whether in east or west longitude. 

Give the latitude and longitude of New York, Quito, Tokio, Rio de 
Janeiro, Calcutta, and Cape Town. 

What city in Europe has the same latitude as New York? What 
is its longitude? Name all the places on this parallel of latitude. 

Give the latitude and longitude of the Hawaiian Islands. Where 
is Iceland? What is the latitude and longitude of the mouth of the 
Amazon River? What city has the same latitude? Name all other 
places in the same latitude. 

How many degrees from the most eastern to the most western point 
of the United States and her territories? What part of the entire 
distance around the world is this? How many degrees from this most 
western point to Pekin? Are these points in the same longitude? 
What large island is partly in east and partly in west longitude? What 
island has the greatest east longitude? To what country does this 
island belong? The man who first sailed around the world stopped at 
this island, and found some very peculiar people. Can you tell any 
thing about them? Not far from here is another island that is impor- 
tant for its coaling stations, and the United States controls one of its 
ports. Can you name the island, and give its latitude and longitude? 

Name all of the islands that have no latitude. Are there any that 
have no longitude? Are there any cities that have no longitude? 

Ask five questions for your classmates to answer. 

What ocean current is off the coast of England? Where does it 
come from? Where does it go? It sometimes washes trees ashore; 
what kind of trees do you think they are? Does it affect the climate of 
England? Which side of Iceland is the warmer? Why? Is Iceland 
warmer or colder than Greenland? 

When warm and cold currents come together, they produce fogs. 
What parts of the ocean do you think are most liable to have fogs? 
The waters of the North Sea are cold, of the English Channel warm. 
What would be the result at London? 



TEST QUESTIONS. 43 

New Orleans has the same latitude as Coquimbo (Chili). Which is 
the warmer? Which is the warmer, the eastern or the western coast of 
the United States? 

What two mountain ranges in the western part of the United 
States? What range in the eastern part? What ranges in South 
America? What is the general direction of these ranges? 

Name and locate the ranges in Europe that are given on the globe. 
What is their general direction? While Europe and Asia are usually 
called two continents, they are really but one continent divided into 
two parts by a mountain range. What is it called? Do the mountains 
of Asia run in the same general direction as those of Europe? Name 
the most prominent range in Asia. They are the tallest mountains in 
the world, and Asia is the largest body of land. 

In what direction is the greatest extension of North and South 
America? Europe? Asia? What comparison do you notice in regard 
to this and the length of the mountain ranges? What comparison do 
you notice in regard to the length of the coast lines and the mountain 
ranges? In what part' of a continent do you think you would usually 
find the longest ranges of mountains? The tallest mountains? 

Where are the desert regions? Where are the largest lakes? 
Inland seas? Where is the longest river? What is the latitude of its 
mouth? Why could there not be so long a river in Asia? What is the 
longest river in Africa?* 

* Continue this line of work until the entire surface of the globe 
is familiar to the pupils. 



CHAPTER VII. 

LONGITUDE AND TIME. 

In the last lesson, I told you that you would 
have to understand all about latitude and longitude 
before I could tell you why the days are longer in 
summer than they are in winter. Sailors are obliged 
to understand latitude and longitude for another 
reason. If they did not, they could not tell where 
they were when crossing the ocean, and might sail 
for months and never find land. After a storm they 
find where the winds have driven the ship, by finding 
the latitude and longitude of the point where they 
happen to be. Let me tell you what they do, and 
see if you can tell me in what direction the winds 
have been blowing. You cannot do this unless you 
can tell the direction of the hour-circles that have 
earlier or later time than the actual time given 
by the meridian. 

If I should set my watch by the local (not the 
" Standard") time at Chicago, and travel to some dis- 
tant place, I should still have Chicago time ; and, if I 
should look at my watch to see what time it was, it 



TIME. 45 

would not give me the actual time of the place where 
I was stoppings but the time at Chicago for that 
moment ; and, by seeing whether the actual time was 
earlier or later, I could tell whether I was east or west 
of Chicago. Suppose I should look at my watch 
shortly after noon at the place where I was stopping, 
and it told me that it was sixteen minutes past 2 
o'clock, which would really be the time at that 
moment in Chicago. Can you tell me in what direc- 
tion the place would be from Chicago? Now, if I 
should find the latitude, it would tell just where I 
was located. The city is about four degrees south 
of Chicago. What city is it? 

If a ship should leave New York, the captain 
would carry New York time; and, when the ship 
crossed the sun's meridian, he would know that it 
was the noon hour by the true time. If he should 
look at his timepiece to see what time it was in 
New York at that moment, he could tell in what 
direction he had sailed, and how many degrees he 
had gone ; so he could tell how many degrees east or 
west of New York the ship was. 

Suppose that he should find that it was 9 o'clock 
a. m. by the ship's chronometer, for that is what they 
call the ship's clock, what is the direction? How 
many degrees is the ship from New York? If it 



4G LONGITUDE AND TIME. 

is on the same parallel of latitude as Cuba, and it 
is the noon hour on the ship's meridian, and the 
ship's chronometer says that it is 5:30 p. m., New 
York time, about what is its latitude and longitude ? 
Near what islands is it? Can it get back to New 
York without crossing the equator? Why? 

In another lesson I will tell you how sailors find 
their latitude, and then you can see how they cross 
the ocean without losing their way. 

There are two ways by which you can change 
longitude into time, and you will find that your 
Tellurian will do it much easier than your arithmetic. 
Let us find the difference in time between London 
and St. Petersburg. This will be one of the easiest 
problems that I could give you, for London is on 
the meridian of Greenwich, so you can begin at 
zero to count. 

Fix the meridian circle so that London will be at 
its eastern edge, that is, so that the meridian of 
Greenwich will be just under the eastern edge of 
the meridian circle; then rotate the globe toward 
the west. You will pass over two hour-circles before 
you reach St. Petersburg, and you will find St. 
Petersburg about one-fourth of a degree east of the 
second hour-circle. By looking on the equator and 
counting the degrees, you will find fifteen between 



TIME. 47 

any two hour-circles ; so one degree must be equal 
to one-fifteenth of an hour, or four minutes, and 
one-fourth of a degree must be equal to one minute. 
I would not try to get the time nearer than minutes. 
You can easily see that the difference of time between 
London and St. Petersburg is two hours and one 
minute. It would be better, however, to count from 
the city that is farthest east to the western city, 
for then you would be rotating the globe in the 
direction in which the earth revolves on her axis- 
Let us find the difference in time between London 
and New- York. London is the more eastern city, so 
it will be the proper place at which to begin to 
count. Do as you did before, — fix the meridian circle 
at the meridian of London, rotate the globe toward 
the east and count the hour circles as they pass under 
the meridian circle. You will notice that four hour- 
circles go under the meridian circle before you reach 
New York, and that New York will come to the 
meridian circle just before you reach the next hour- 
circle. Look at the equator, and count the degrees 
passed over between the last hour-circle and the 
meridian of New York. You will find that there 
are fourteen, and since each is equal to four minutes, 
the distance will equal fifty-six minutes; so the 
difference in time between London and New York 



48 LONGITUDE AND TIME. 

is four hours and fifty-six minutes. Find the differ- 
ence in time between London and Hawaii. How 
many degrees is it? Multiply this number by four, 
and what will it give ? How many hours and minutes 
is it equal to? 

Find the difference in time between New York 
and Hawaii. The following questions will assist you: 
How many degrees from New York to the first hour- 
circle west of New York? How many minutes in 
time to this hour-circle? How many hour-circles 
between New York and Hawaii ? How many degrees 
between the first hour-circle east of Hawaii and 
Hawaii? How many minutes? Adding the hours 
and minutes that you have found, will make the 
number of hours and minutes that represent the 
difference in time between these places. 

Find the difference in time between St. Petersburg 
and New York in the same way. How many degrees 
is it? What is the difference in time between San 
Francisco and Hawaii? What is the difference in 
degrees ? 

What is the difference in time between New York 
and San Francisco ? What is the difference in degrees ? 
When it is one o'clock p. m. in New York, what time 
is it in San Francisco ? What time is it in London ? 
The direction in which the earth rotates will tell you 



TIME. 49 

whether it is earlier or later. A telegram sent from 
New York to San Francisco reaches San Francisco at 
noon. It takes less than a minute ; at what time was 
it sent? 

• Yesterday's Liverpool markets are quoted in our 
morning papers. Suppose the markets close at 3 p. m., 
could our evening papers quote them? At what time 
would the cablegram reach Chicago if it was sent at 
once and there was no delay ? 

The following is a table of the longitudes of 
several places as given in the Gazetteer. It will be 
of assistance to you in making problems similar to 
those given, and will furnish you with proof of the 
correctness of your work, 

Antipodes East longitude 178°, 43'. 

Hawaii W^est longitude 155°, 40'. 

San Francisco West longitude 122°, 24'. 

New York West longitude 74°, 00'. 

London 00°, 00'. 

Cape North East longitude 25°, 46'. 

St. Petersburg East longitude 30°, 18'. 

Apia ... West longitude 171°, 21'. 

Juan Fernandez .West longitude 78°, 53'. 

At the close of Chapter IV. you will find the table 
of circular measure, which is used in the study of 
arithmetic for finding longitude and time. The fol- 
lowing table of comparisons will also be useful; 

360 degrees, — 24 hours. 
15 degrees, — 1 hour. 
J degree, — 4 mi niit.ee, 



50 



LONGITUDE AND TIME. 



Seconds of distance and of time need not be con- 
sidered in the problems that follow, so they are not 
included in the preceding table. The diagram below 
will also assist in understanding the table, and the rule 
for the solution of the problems that are given: 




The circle represents the equator, and D is the 
longitude of Greenwich. The first 90 degrees of 
west longitude are divided into six parts, each equal 
to one hour, and each equal to fifteen degrees. The 
line C D is the dividing line between east and west 
longitude. To find the difference between 30° west 
longitude and 90° west longitude, you subtract 



DIFFERENCE IN TIME. 51 

How many degrees is it ? How many degrees is it 
from 30° west longitude to 45° east longitude? Did 
you find it by adding or subtracting? How many 
degrees is it from 90° west longitude to 135° west 
longitude? Did you add, or subtract, to find it? How 
many degrees is it from 185° west longitude to 135° 
east longitude? Did you add, or subtract, to find it? 
Do you add, or subtract, to find the difference when 
both are in west longitude? Do you add, or subtract, 
to find the difference when one is in west longitude 
and the other is in east longitude ? When both are in 
east longitude how do you find the difference ? 

I. Find the difference in longitude. 
II. Divide this difference by 15, and the result 
will be the difference in hours. If you have a remain- 
der, multiply it by 4, and the result will be the 
number of minutes. 

1. When it is noon at San Francisco, what time is it at New York? 

SOLUTION. 

San Francisco is 122° w T est longitude. f 15 )±r 

New York is 74° west longitude. J 3 and 3 remainder; that 



tn-^. .T^T I 1S > 3 hours and 3 times 4 

Difference, 48° 1rt . 

^ minutes, or 12 minutes. 

As New York is east of San Francisco, it would be later there 
than at San Francisco. Hence New York time would be 3h. and 
12m. p. m. 



52 LONGITUDE AND TIME. 

2. What is the difference in time between Cape North and London? 
If it is noon at London, what time is it at Cape North? If it is noon at 
Cape North, what time is it at London? Try the same problem with 
the globe. 

3. An explosion occurs at St. Petersburg at 8 a. m. The news is 
telegraphed, without loss of time, to the London and New York papers 
which go to press at 3 a. m. Can they print the account in the morning 
issues? 

4. A sea captain having New York local time, looks at his chro- 
nometer when his ship's meridian is at the noon hour, and finds that 
it indicates 12 minutes after 7 p. m. He is in latitude 49° 42' south. 
Near what islands is he? 

Since each degree is equal to 4 minutes in time, the following rule 
affords an easy method of changing longitude to time: 

I. Find the difference of longitude in degrees 
between the given places. 

II. Multiply this difference by 4. The product 
will equal the number of minutes in the difference 
of their times. Change the number of minutes to 
hours and minutes. 

5. Find the difference in time between New York and Apia. 

Apia is 171° 21/ west longitude. 

New York 74° 00 ' west longitude. 

Difference 97° 21' 
The 21 minutes is equal to a little more than one-third of a degree. 
Then 97% x 4 = 389, and 389 minutes equals 6 hours and 29 minutes, 
which is the difference in time between Apia and New York. 

6. When it is noon at Wellington, what time is it at Berlin? 

7. What is the difference in time between Melbourne and Chicago? 

8. On the 23d day of June, the sun rises at 5 o'clock in New 
Orleans. What time is it then in London? What time is it then in 
Wellington? New Zealand? 



CHAPTER VIII. 



DAYS AKD NIGHTS. 



The sun is our principal source of light, and 
shines on half of the earth all the time. I have 
already told you that the earth is divided into 
hemispheres, and that the equator is the dividing 
line between the Northern and the Southern Hemi- 
sphere; also that two of the meridians divide it into 
an Eastern and a Western Hemisphere. I wonder 
if you can tell where those meridians are. 

There are four more hemispheres that I want to 
tell you about, a Lcmd, a Water, a Day, and a Night 
Hemisphere. If you draw a great circle around the 
globe so that it will pass through a point located 
at 45 degrees north latitude, and 150 degrees west 
longitude, and another point at 45 degrees south 
latitude and 30 degrees east longitude, a greater part 
of the land will be north of this line, and most of 
the water on the earth's surface will be south of 
this line. Can you find these points, and stretch a 
rubber band around the globe so as to show the 
Land and Water Hemisphere? 

(53) 



54 DAYS AND NIGHTS. 

The day and night circle is a great circle, and, in 
using the globe, we call it the Sunrise and Sunset 
Circle. It divides the earth into two equal parts, 
which I have called the Day and Night Hemispheres. 
These hemispheres are changing their position all 
the time, and in this respect are unlike the Northern 
and Southern Hemispheres, whose boundaries are 
fixed by the equator, or the Eastern and Western 
Hemispheres, whose boundaries have been fixed by 
men who have made geography their special study. 
The Northern and Southern Hemispheres cannot 
change their positions, for they are separated by the 
equator, a fixed line midway between the poles, 
which are fixed points, being the ends of the earth's 
axis. This axis does not change its position except 
by a very small amount in thousands of years, so we 
may say that it is fixed. 

Now, what has all of this to do with the Day 
and Night Hemispheres? I will tell you. I wanted 
to show you the difference between hemispheres that 
could not change their positions, and those that were 
constantly changing, like the Day and Night Hemi- 
spheres. The Day Hemisphere is the half of the 
earth that is toward the sun, and the opposite half 
is the Night Hemisphere. If you will rotate the 
globe, you will see that places are constantly passing 



THE DAY HEMISPHERE. 55 

under the sunset circle from day into night; and, 
when the rotation brings your own home under the 
sunset circle, you say that the sun is going down; 
still, you know that the sun does not move in this 
way, but only appears to move. 

If you were riding on a train of cars, and should 
look out of the window at the fence-posts along the 
track, they would appear to be going in the direction 
opposite to that in which you were going, and the 
fence would appear to be actually moving, just the 
same as the sun appears to be moving when it is 
going down. 

Kotate the globe until New York is under the 
sunrise circle, and it will represent the position of 
New York when the sun first appears in the eastern 
sky. As you continue to rotate the globe, it will 
illustrate New York's change of position, which 
causes the sun to appear to rise above tie ground. 
If you watch the needle until the first hour-circle 
comes under it, it will tell just how long the sun 
has been up; but I will tell you all about this in 
the lesson on the " Length of Days and Nights." 
You will see, as you continue the rotation, that New 
York moves toward the noon meridian, passes it, 
moves on toward the sunset circle, reaching it just 
at sun -down, and passes into the night hemisphere. 



m BAYS AND NIGHTS, 

It then moves toward the midnight meridian, passes 
it at 12 o'clock, and goes on toward the sunrise 
circle. When it reaches this circle, the earth has 
made one revolution on her axis, which has taken 
just twenty-four hours; and, no matter if the day is 
longer than the night, or the night longer than the 
day, both together have the same number of hours 
that it takes the earth to make her daily revolution. 

So you see, that, while the day hemisphere is 
fixed in relation to the sun, it appears to go around 
the earth from east to west, constantly bringing 
places into the day hemisphere, and leaving in the 
night hemisphere the places it has passed over ; but, 
really, it is the rotation of the earth that does this, 
and the day hemisphere does not move at all, but, 
like the fence-posts, only appears to move. Each 
place is on the side of the earth on which the sun 
shines, for a part of the twenty-four hours only ; and, 
for the remainder of the twenty-four hours, it is on 
the dark side of the earth. Can you see how this 
is true? 

In another lesson I will tell you why the rotation 
of the earth does not carry some places on its surface 
into the night hemisphere for several months at a time, 
and then for several months does not carry them out 
of it. For weeks they have long moonlight nights, 



THE Mou A'W DAY. 57 

with a few hours of twilight ; but the sun does not 
appear. At last it just rises above the horizon, and 
in a few minutes sets. After this the days grow 
rapidly longer, until the sun does not go down at 
all for the remainder of the year. Day and night 
do not mean the same, to people who live in these 
places, as they do to us. 

The moon has but one day and night for twenty- 
nine and one-half days and nights; so a day and a 
night on the moon are each a little more than two 
weeks long. If you watch the moon for one of its 
days and nights, you can see just how the days and 
nights on the earth would look if you could be on 
the moon and watch them, and see how the night 
appears to follow the day. You can see just how 
the day hemisphere looks, and that it is always on 
the side toward the sun. You can also see how it 
is, that, in like manner, the rotation of the earth 
actually carries places across the day and night 
hemisphere. 

Begin to watch the moon when it first appears 
in the western sky, just after sun-down. You will 
see only a narrow strip of the day hemisphere on 
the western edge, a shining crescent, the new moon, 
made luminous by its reflection of the sunlight. 
Almost all of the night hemisphere is toward you, 



58 DAYS AND NIGHTS. 

so that you do not see the moon as a round body, 
unless the earth's atmosphere is very clear, when a 
faint outline of the moon is made visible by the 
light reflected from the earth. If you watch the 
moon each night, you will see that the part that 
shines, grows larger for two weeks ; in other words, 
the day hemisphere has in two weeks crossed over 
that part of the moon's surface that is toward the 
earth, until you see the whole of the day hemi- 
sphere, the full moon appearing in the eastern sky 
just after sun-down. 

The next night it will look a little flattened on 
one side, and the next night still more so, until, at 
the end of the week, one-half of the moon will be 
bright, and the other half dark; that is, you will 
see half of the day hemisphere, — one-quarter of the 
moon, — and half of the night hemisphere. At the 
end of another week the whole of the night hemi- 
sphere, or the dark side, will be toward you, and 
you cannot see the moon afc all ; but, in a day or 
two, you will see it again in the western sky, just 
after sun -down, a new moon, just as you saw it 
twenty- nine days before, when you first began to 
watch it. 

The bright part of the moon is always toward 
the sun; and, if you should draw a line from one 



THE MOON. 59 

point of the crescent to the other, and then another 
line through the middle of this line and the middle 
of the crescent, it would point directly at the sun.* 

* See Chapter XIV. 



CHAPTER IX. 

YEARLY REVOLUTION OF THE EARTH. 

So far you have studied only one revolution of 
the earth. It has another, its revolution around the 
sun, or yearly revolution, which causes the changes of 
the seasons, and the constant variation in the length 
of the days and nights. 

Place the earth at the 2Qth* day of March, in its 
orbit, and press the sun pointer down close to its 
surface, then move the orbit bar so that the index 
approaches April, and you will notice that the sun 
pointer has moved from the equator to a little north 
of the equator. If you rotate the earth the sun 
pointer will point to the same parallel daring the 
entire revolution. If you move the orbit bar so 
that the calendar index points at the 1st of May, 
you will notice that the sun pointer is still farther 
away from the equator, and that it will remain over 
the same parallel during an entire rotation of the 
globe. If you move the orbit bar again, so that the 

* The exact time is not the same for different portions of the 
earth's surface; and, for the same portions, it varies each year, but 
within a small limit. 

(60) 



YEARL Y BE VOL UTION. 61 

calendar index will show that the earth is at that 
point in her orbit which we call June 1st, you will 
see that the sun pointer is still farther north; and, 
when the earth reaches June 2 1st, the sun pointer 
will point very near to the parallel of 23^° north 
latitude. When the earth passes this point, the sun 
pointer will move back south again, and cross the 
equator on the 2 2d of September. 

The direct rays of the sun continue southward 
till the 21st of December, when they have reached 
their southern limit, and the direct rays are at about 
23^° south latitude, the southern tropic, or turning 
point, of the direct rays. Continuing the revolution 
of the earth around the sun, you will see that the 
direct rays travel northward, and reach the equator 
on the 20th day of March. This is called the yearly 
revolution of the earth, and it requires a little more 
than 365 days for its completion. 

There is a figure on the globe called the Ana- 
lem?na, which gives the latitude of the direct rays of 
the sun for each day in the year, and sometimes it 
has a scale for the comparison of sun time with the 
time shown by a clock dial. You will find this figure 
on your globe just west of the northern part of South 
America, with the equator dividing it into two equal 
portions. 



62 REVOLUTION OF THE EARTH. 

Place the earth again at the 20th day of March, 
in its orbit, and rotate it so that the analemma will 
be under the direct rays of the sun; then move the 
earth around in the orbit, keeping the analemma 
under the direct rays of the sun all of the time that 
you are moving the orbit arm from March through 
each month till you get back to March again. Watch 
the sun pointer as it goes north, turns back south, 
crosses the equator, and goes to the southern point of 
the analemma, turns north again, and reaches the 
starting point in March, passing through all of the 
months of the year. This is an easy way to find the 
position of the earth in its orbit, and to get the lati- 
tude of the direct rays of the sun for any day in the 
year. It is important to consider the latitude of the 
sun's rays, when studying climate, and the length of 
the days and nights. 

The earth's orbit has twelve divisions, called 
Signs, which correspond to the months of the year. 
The following table gives the name of each season, 
with the names of its signs, and of their correspond- 
ing months. 

( Aries. March. ( Libra, September. 

Spring.. < Taurus. April. Autumn ■] Scorpio, October. 

(Gemini, May. ( Sagittarius, November. 

( Cancer, June. ( Capricornus.December. 

Summer ] Leo. July. Winter., j Aquarius. January. 

( Virgo, August. ( Pisces, February. 



THE SIGNS. 63 

You have probably noticed the names of two of the 
preceding signs in your geography, in connection with 
the names of two parallels of latitude, the Tropic of 
. and the Tropic of Capricorn. "Tropic" comes 
from a word that means to turn. During the spring 
months the sun appears to come north until the earth 
has passed nearly through the sign of , Cancer, and 
the direct or perpendicular rays have reached the 
Tropic of Cancer; then the sun seems to turn and 
go south until the earth is nearly through the sign of 
Capricorn, and then to turn again and go north for 
six months. 

While at the turning point, it seems to stand still 
for a few T days, and we say that the sun is at his 
Solstice. This word is derived from two words, Sol, 
which means "sun," and another word that means "to 
stand still. 5 ' The solstice in June is called the 
Summer Solstice, and that in December the Winter 
Solstice. The point in the earth's orbit where the 
direct rays of the sun cross the equator when spring 
begins is called the Vernal Equinox, and the point 
where they cross at the beginning of autumn, the 
Autumnal Equinox. Can you give the dates when 
the earth is at these points \ 

This moving to and fro of the direct rays of the 
sun between the tropics is caused by the earth's 



64 REVOLUTION OF THE EARTH. 

yearly revolution around the sun. This revolution 
causes the changes of the seasons, and makes the days 
and nights of unequal length, except at the equinoxes, 
when all places on the earth's surface, save a small 
space at each pole, have equal days and nights. The 
word " equinox" is derived from ceqaus y meaning 
" equal/' and nox, u night." All places on the equator 
have equal days and nights during the entire year; 
but the farther you go from the equator the greater 
will be their difference in length, except at the time 
of the equinoxes. Also the farther the earth is from 
its equinoxes, the greater this difference will be; and 
when it has reached the point in its orbit most dis- 
tant from the equinox, this difference will be at its 
greatest. What are the points in the earth's orbit 
farthest from the equinoxes called ? At what dates 
does the earth reach them?* 

1. Place the earth at the vernal equinox, and rotate. What do you 
notice regarding the latitude of the direct rays of the sun? 

* Four seasons, 1894; central time: Vernal equinox, sun enters 
Aries, March 20th. Summer solstice, sun enters Cancer, June 2Jst. 
Autumnal equinox, sun enters Libra, September 22d P Winter solstice, 
pun enters Capricornus, December 21st,. 



EXPERIMENTS. 65 

2. Move the orbit bar from the vernal equinox to the summer 
solstice. Is the northward movement of the direct rays uniform? If 
not, through what degrees of latitude do they pass most rapidly? How 
many days does it take for them to pass between these two points? 
How many degrees do they travel during the first thirty days? The 
second thirty days? During the remainder of the time? How many 
degrees do they pass through during the month of June? 

3. Move the orbit bar from the summer solstice to the winter 
solstice. Tell what you notice regarding the rate at which the direct 
rays travel south, how long it takes them to reach the Tropic of 
Capricorn, and anything else you may have noticed. 

4. Move the orbit bar back to the vernal equinox again. How 
many days has it taken to make the entire revolution? How many 
to go from the winter solstice to the vernal equinox? Is the period of 
time that the days and nights are nearly equal, greater or shorter than 
the time of their greatest difference? Why? 



CHAPTER X. 



LENGTH OF DAYS AND NIGHTS. 




The length of the day at any place on the 
earth's surface depends upon the time it takes for 
that place to cross the day hemisphere; and the 
difference between the length of the day and twenty- 

(66) 



THE DAY HEMISPHERE. 67 

four hours, is the length of the night for all places 
in the same latitude. 

After the sun has crossed the equator, the entire 
length of that part of a meridian circle illuminated 
in any one day does not come into the sunlight at 
the same moment; but, if it is between the 20th of 
March and the 22d of September, the sun rises at 
the northern end of that part of the meridian circle 
before it does at the southern end, and sets at the 
southern end before it does at the northern. 

The figure opposite represents the day hemisphere 
as it would appear on a midsummer's day, with the 
polar circle entirely within the circle of illumina- 
tion, shown by the circumference or boundary line of 
the figure. It can also be seen that all the merid- 
ians cross at the pole. As the earth rotates on its 
axis, you see that no point within the polar circle 
is carried out of sight of the sun during an entire 
revolution. The point K has been in the sunlight 
since it left the point B, while the sun is just rising 
at the point D, which is directly south of K, for the 
same meridian passes through it. When D reaches 
G, the sun will set, but it will not set at K till K 
has reached I, which will be several hours after sun- 
down at G. You can now refer to the Tellurian. 

* See Chapter IX. 



68 DAYS AND NIGHTS. 

Place the earth at the 20th day of March, in its 
orbit, and, by rotating, you will see that the entire 
length of each meridian passes under the sunrise 
circle at the same moment; that is, every place has 
sunrise at the same time that other places exactly 
north or south of it have; also, that all places on 
the same meridian pass under the sunset circle and 
have sunset at the same moment, so that the day 
of each place is of the same length as the day at 
any other of these places; and this, of course, would 
also make the nights equal. They do not remain 
equal, however, as you will notice by moving the 
earth forward in its orbit; but the days will grow 
longer and the nights shorter at all places in north 
latitude, as the earth advances, until the summer 
solstice is reached. Let us see why this is true. 

Press the sun pointer close to the surface of the 
globe, and measure the distance from its point to 
several points in the day and night circle, and you 
will see that it is at the same distance all the way 
round, and that the direct rays of the sun, repre- 
sented by the sun pointer, are in the exact center of 
the day and night circle, or the day hemisphere. 
As the earth advances in its orbit the direct rays 
move north, and the entire day hemisphere moves 
north also. On the 15 th day of April the direct 



DAYS AND NIGHTS. 69 

rays will be at 10° north latitude; the southern 
limit of the day hemisphere will be just 10° north 
of the south pole, and all of the earth's surface 
north of 80° north latitude will be in the day hemi- 
sphere. The south pole will have no more sunshine 
for nearly six months, while for the same time the 
sun will shine on the north pole. 

As you rotate the globe the northern part of each 
meridian will come into the day hemisphere before 
the southern part does, and the southern part will 
leave the day hemisphere before the northern part 
does; so the sun will rise earlier and set later at the 
northern part of the meridians than at the southern ; 
that is, the days will be longer in northern than in 
southern latitudes. The farther north, the longer the 
day will be, and the longer the day the shorter the 
night. This is because one end of the earth's axis 
around which all the meridians rotate is within the 
day hemisphere, and it will be as far from this end 
(the north pole) to the nearest point of the day and 
night circle as the direct rays of light are north oi 
the equator. Measure it, and see for yourself. 

When the earth has reached the summer solstice 
the direct rays will be at about 23^° north latitude, 
the day hemisphere will include all of the arctic 
circle, and any one who is within the arctic circle 



70 DAYS AND N1GHT& 

can see the sun for the entire twenty-four hours. It 
will appear to travel around in a circle, and, if the 
position of observation is near the arctic circle, the 
sun will appear to nearly touch the horizon at mid- 
night, and at noon to be a number of degrees above 
it. If the observer could be at the north pole, the 
sun would appear to describe a circle of which he 
would be the center, and, as the direct rays traveled 
toward the autumnal equinox, it would describe 
larger and larger circles each day, till finally it would 
make a circle just above the horizon all around, and 
in a day or two would go out of sight. Can you 
imagine how it would appear? 

I have spoken a number of times about the Noon 
Meridian, and now I want to tell you about the 
meridian directly opposite, the Midnight Meridian. 
When the sun is at the summer solstice, the northern 
end of the midnight meridian, from the point where 
it crosses the arctic circle to the north pole, is in 
the day hemisphere, the sun can be seen from all 
points between these limits, and at midnight, in 
looking at the sun, you would look toward the 
north pole. It is called the Midnight Sun, and is 
always seen directly north of the observer. * How can 
this be, when the sun never gets farther north than 
the Tropic of Cancer? Your Tellurian will tell you. 



MIDNIGHT MERIDIAN. 71 

When the meridian of 75° west longitude is 
the noon meridian, what meridian is the midnight 
meridian? When the direct rays are at 20° north 
latitude, how far south of the north pole can the 
observer go and still see the midnight sun? In what 
direction will he look? Is the sun really north of 
the north pole? 

So far we have confined our observations to the 
northern hemisphere during the spring and summer 
months. Let us see how it is with the southern 
hemisphere for the same time. Let us begin with 
our vernal equinox again; — and I say our vernal 
equinox, for it is the autumnal equinox to the people 
who live in the southern hemisphere, as will be 
shown in the chapter on " Climate." At this time 
the southern hemisphere, like the northern, has equal 
days and nights, for the entire meridian passes under 
the sunrise or sunset circle at the same time; but, as 
soon as the sun passes north of the equator, the 
southern hemisphere seems to turn away from the 
sun, and the south pole does not emerge from the 
night hemisphere for six months. The southern 
ends of the meridians pass quickly across the day 
hemisphere, and continue for a long time in the 
night hemisphere ; and in length the days and nights 
are the reverse of what they are at the same time in 



72 DAYS AND NIGHTS. 

the northern hemisphere. New Zealand has about 
the same latitude south that Illinois and Wisconsin 
have north, and the nights of New Zealand will be 
of the same length as that of the days in Illinois 
and Wisconsin at the same time; so that, while the 
latter are having long days and short nights, the 
former is having long nights and short days. 

When the sun reaches his summer solstice in the 
northern hemisphere, the people in the southern 
hemisphere say that it is at the winter solstice; for 
they are having winter there, and their days are 
short, and their nights long. If you place the earth 
at the 21st day of June in its orbit, and rotate it, 
you will see that this is true. 

In a former lesson I told you that the rotation of 
the earth carried all places on its surface around in 
a circle, and you have had an opportunity to see that 
it is true. Now I want you to notice another thing, 
which will tell you why the days and nights are 
not always of the same length; and which will be 
the most noticeable at the time of the summer 
solstice, when all places within the arctic circle 
make the entire circle in the day . hemisphere, and 
a place at 70° north latitude makes nearly all of 
the circle in the day hemisphere. As you go farther 
south, these parts of a circle, or arcs, as they are 



EQUAL ARCS. 73 

called, grow more nearly equal until you reach the 
equator, where the day and night circle divides it 
into two equal parts, and here the days and nights 
are equal. But at 40° south latitude, the day and 
night circle divides the parallel into two unequal 
arcs, the longer arc being in the night hemisphere, 
and the night is longer than the day. By finding 
the number of degrees in these arcs you can easily 
determine the length of the days or nights by 
changing the degrees to minutes. There will be four 
minutes for each degree. 

Study carefully the following rule for finding the 
length of any day or night, and, by using your 
Tellurian, show that the statements made are true: 

I. Move the orbit arm of the Tellurian so that the 
indicator will point to the 21st day of June. The 
polar circle will then just touch the day and night 
circle. 

II. Rotate the globe so that Chicago will be under 
the edge of the sunrise circle. Without moving the 
globe, fix the meridian circle so that any convenient 
hour-circle will be just under its eastern edge. (In 
speaking of any of the circles the eastern edge is 
meant.) 



74 DAYS AND NIGHTS. 

III. Rotate the globe toward the east, and count 
the hour-circles as they come to the eastern edge of 
the meridian circle. Continue the rotation until 
Chicago comes to the night circle. The number of 
hour-circles that pass under the meridian circle will 
be the number of hours, and the number of degrees 
between the last hour-circle and the eastern edge of 
the meridian circle, when multiplied by four, the 
number of remaining minutes, in the length of 
the day. 

IV. The difference between the length of the day 
and twenty-four hours, will be the length of the 
night. 

Perhaps it may be well to leave the study and 
the application of the above rule until you have 
completed the next chapter. 



CHAPTER XL 



(1.) HOW TO COMPUTE THE LENGTH OF DAYS AND NIGHTS. 

(2.) TWILIGHT. 



Z™ 




Ill 



In the figure above I have represented the earth as 
it would appear to an observer if he could be situated 
so as to look at it from a station where the day and 
night circle, A E, would appear as a diameter, or where 
it would appear the same as the moon does when in 

(75) 



16 DAYS AND NIGHTS. 

quadrature. The dotted line NS is the earth's axis, 
around which all places on the earth's surface rotate 
once in twenty-four hours; the arrows represent the 
direction of the rays of sunlight; the light portion 
represents one half of the day hemisphere, or from 
sunrise till noon, and the dark portion, one half of the 
night hemisphere, or from midnight till sunrise, and 
includes the twilight belt. It is on the 21st day of 
June, the sun has reached the summer solstice, and, in 
the northern hemisphere, the days are longer and the 
nights shorter than at any other time during the year. 
The first arrow represents the direct rays of the sun, 
which strike the earth at the Tropic of Cancer; the 
second arrow, a ray of sunlight that strikes the earth 
at A, which is the greatest distance from the direct 
rays that it is possible for sunlight to touch the earth. 
Since all places between A and N rotate about N, 
they will be in the sunlight during the entire revolu- 
tion; but, when the direct rays move south, the point 
A will approach N, and the circle of continuous sun- 
light will grow smaller till A has reached N, which it 
will do on the 2 2d of September. (See figure on 
page 82.) When the point A is at N, the sunrise and 
sunset circle will coincide with two of the earth's 
meridians that are directly opposite to each other. 
The sun will be rising at every point in one of them, 



COMPUTING TIME. 77 

and setting at every point in the other. Two other 
meridians constitute the circumference of the figure; 
one of which is the noon meridian, and the other the 
midnight meridian. Name the points through which 
they pass. 

Let us study the earth in the two positions men- 
tioned,— at the summer solstice, represented in the fig- 
ure, and at the autumnal equinox (see page 82), where 
the earth will be when the point A is at N, — and see 
if we can learn how to compute the length of days 
and nights, and then we can use the same method for 
the computation of days, nights, and twilights for any 
time during the year. 

We will begin with the first position, with the 
earth at that point in her orbit called the summer sol- 
stice, and suppose that the city of New Orleans is 
located at the star C, a point in the midnight meridian. 
The rotation of the earth will carry it in the direction 
of the curved line CG. The dots along this line show 
the points at which it will arrive each hour from mid- 
night till noon. It enters the twilight belt about 
3 o'clock, and requires nearly two hours to pass 
through it and come in sight of the sun, which it 
does one minute before 5 o'clock, the time of sunrise 
at New Orleans for this date. At 6 o'clock it has 
reached the meridian NS, and at 10 o'clock, the star 



78 DAYS AND NIGHTS. 

F. If you now measure its distance from the sunrise 
circle, you will find that it is nearly the same as the 
distance from the midnight meridian to the sunrise 
circle. It is still two hours till noon, so the day at 
New Orleans for this time of the year is a little more 
than four hours longer than the night. 

Let us follow this through with the Tellurian, and 
then you can try the same experiment with Chicago, 
and see if you can tell the length of the day and night, 
the time of sunrise, and the difference in the length of 
the day and night. Keep the earth at the same point 
in its orbit, note carefully each step as it is taken, and 
then you will make no failure. 

Place the earth at the 21st day of June, which is 
its position in the figure at the beginning of this chap- 
ter, press the sun pointer down close to its surface, 
rotate till the meridian of Greenwich comes directly 
underneath the pointer, and then fix the meridian 
circle at the meridian of 180 degrees. The pointer 
will now serve the purpose of the sun's meridian, 
and the meridian circle that of the midnight meridian, 
so that, as the earth rotates, these two points will 
remain fixed, and you can count the hour-circles as 
they pass under them. In this way we can get the 
difference in time without getting the difference in 
longitude as the arithmetics teach. 



COMPUTING TIME. 79 

Now, to find the time it takes for a place to pass 
from one point to another, as from sunrise to noon, 
rotate the globe till the place that you are observing 
is at the starting point. With the globe at rest in 
this position, find the number of degrees, if any, from 
the eastern edge of the meridian circle to the first 
hour-circle west of it, and multiply it by four to get 
the number of minutes; then, as you rotate the 
globe toward the east, count the hour-circles (after the 
first) that pass the meridian circle till the place 
has reached the given point, to get the number of 
hours. Then count the remaining degrees, if any, 
between the last hour-circle and the meridian circle, 
and this amount, together with the number of hour 
spaces, will give you the time required for the place 
to pass to the given point. 

In this way let us count the time it takes for New 
Orleans to pass from the midnight meridian to the 
twilight belt, and then to the sunrise circle, which it 
will reach at one minute before 5 o'clock. Continue 
the rotation till New Orleans comes to the sun's merid- 
ian, or noon, counting as you go, and you will find 
that it will be seven hours and one minute till noon. 

You may now try the same experiment with 
Chicago, which you will notice is a short distance from 
the first hour-circle west of it. You will also notice 



80 DAYS AND NIGHTS. 

that the sun rises earlier, that the night is shorter, and 
that the day is longer. Be careful to see where the 
meridian crosses the equator, and remember that each 
degree is four minutes of time, and that 15 degrees is 
one hour of time. After you have tried this experi- 
ment, see if you can compute the time of sunrise at 
Chicago on April 25th. 

In finding the length of the day, it is easier to 
move the meridian circle to the position of the sun's 
meridian, and then count the degrees* and hours that 
pass under it while the place that you are experiment- 
ing with rotates from sunrise to sunset. This time 
subtracted from 24 hours gives the length of the 
night. In the same way you can determine the length 
of twilight, by counting the degrees that pass under 
the meridian circle while a place is passing through 
the twilight belt. 

Owing to the elliptical form of the earth's orbit 
and its inclination to the equator, the sun's apparent 
motion through the sky is not uniform; so the days 
are not exactly 24 hours long by the clock, but vary 
a little day by day, till the difference amounts on the 
2d of November to over 16 minutes. A day of sun 
time is the time that it takes for a point on the earth's 
surface to rotate from the sun's meridian clear around 

* Count each degree as four minutes, the spaces between the hour- 
circles as hours. 



THE SUN'S AVERAGE TIME. 81 

to the sun's meridian again; while a day of mean time 
(the time kept by a clock or watch) is 24 hours. 

The time that you find with the Tellurian is sun 
time; and, to make it agree with the clock, it is neces- 
sary to correct it by adding to it, or subtracting from 
it, the difference between the sun's apparent time and 
the mean time, which is the sun's average time, com- 
pared with which the sun's apparent time is either 
slow or fast, according to the position of the earth in 
its orbit. 

Sun time and mean time agree four times a year, on 
April 15th, Jane 14th, September 1st, and December 
24th, and their difference is never more than 16 min- 
utes and 20 seconds sun fast, or 14 minutes and 30 
seconds sun slow, which occurs on November 2d and 
February 11th. This difference is called the Equation 
of Time, and will be found in any good almanac, for 
each day of the year, in a column headed " sun fast " 
or "sun slow." With this correction, you can do quite 
accurate work in finding time with the Tellurian.* 

The following figure represents the earth at the 
time of the equinoxes, the second of the two positions 
previously mentioned. The line AE of the first figure 
coincides with NS in this figure, while A and B of 
this occupy the position of A and B in the first. 

* See "Appendix," lesson on the Analemmn. 



82 



DAYS AND NIGHTS. 







New Orleans is again at midnight, and the dots along 
the curved line show where it will be at the end of 
each hour from midnight till noon. Try the same exper- 
iments that you tried before, and note the differences 
in results. The point A is at the same distance from 
the pole that it was on the 21st of June; but see what 
a change has taken place in regard to the length of its 
days. How will it be ninety days later? Try the 
experiment, and see. 

In this latter figure you will notice a dotted curved 
line surrounding the earth. This represents a stratum 



TWILIGHT. 8:i 

i>f the atmosphere 50 miles in height, the greatest 
height at which it is capable of reflecting sunlight. 
The sunlight in this upper stratum of the atmosphere 
can be seen until the sun is about 18 degrees below 
the horizon. This reflected light produces the phe- 
nomena of twilight. 

If it were not for the twilight, it would become 
dark as soon as the sun went down; but, as it is, the 
first moments of twilight give nearly as strong a light 
as the last moments of sunlight. Each moment after 
sunset the rays of light pass through the atmosphere 
farther above our heads; and the farther they are 
above our heads the less light there is to be reflected, 
until, when the sun is about 18 degrees below the 
horizon, the last rays above us disappear and twilight 
ceases. This would occur in one hour and a quarter if 
the point of observation passed straight across the 
twilight belt; but all places pass through the twilight 
belt in a curve that is inclined to it. This inclination 
varies for different seasons of the year and for different 
latitudes. Many places stay in the twilight belt, at 
certain seasons of the year, during the entire night. 
Find some of them. 

To get the length of the twilight of any place for 
any time, place the earth at the desired date in its 
orbit, then rotate till the place comes to the sunset 



84 DAYS AND NIGHTS. 

circle, fix the meridian circle at any hour-circle, then 
count the degrees that pass under it while the place 
is passing through the twilight belt. 

Now study the rule at the end of Chapter X. very 
carefully, so that you may be able to understand the 
reason for each step. In computing the time of sunrise 
for any place, it will be best to fix the meridian circle 
at the midnight meridian, then bring the given point 
under the meridian circle, and count the time from 
midnight till sunrise. To find the time of sun-down, 
begin with the noon meridian. To find the time be- 
tween two given points, see the chapter on "Longitude 
and Time." 



CHAPTER XII. 

DISTRIBUTION OF LIGHT AND HEAT. 

In Chapter VIII I told you that the sun was the 
source of light; it is also the source of heat; and 
since the sun shines on one-half of the earth all of the 
time, the heat must be greater on that portion of the 
earth's surface than on the part that is in the shadow; 
but all portions of the earth's surface that are in the 
sunlight do noi get the same amount of light and heat. 
Let us inquire into the reason of this, 

I have spoken a number of times about the direct 
rays of sunlight, and you might have inferred that 
there were other than direct rays ; but this would not 
be strictly true, for the rays of light, or heat, as they 
come from the sun are parallel to each other, or 
nearly so, near enough to assume that they are par- 
allel, so that, if the earth's surface were a disc per- 
pendicular to the sun's rays, all places would receive 
the same amount of light and heat, and would have 
the same temperature. The curvature of the earth's 
surface prevents all places, except those in the center 

(85) 



LIGHT AND BEAT. 



of the day hemisphere, from receiving rays of heat and 
light that are perpendicular; and it is the perpendic- 
ular rays that are meant by the " direct rays," as they 
are called in this book. 

The curvature of the earth's surface causes a very 
unequal distribution of light and heat, as you will 
notice by examining the following figure. It will also 
show you the importance of the direct rays, and tell 




3 

-4- 



you why it is so much colder at the poles than it is at 
the equator. Notice, also, that the direct rays are the 
only ones that can be perpendicular to the earth's sur- 
face. 

The figure represents the earth at the time of the 
equinox, and the dotted line AJ is the equator. The 
lines E, F, G, and H, representing rays of light and 
heat, are parallel to each other, and strike the surface 
of the earth at A, B, C, and D, which are at equal dis- 
tances apart; EF and FH are the same distances 



DIRECT AND OBLIQUE RAYS. 87 

apart, and from G to H is one-seventh of the distance 
from E to H. The figures represent equal distances. 

If we could consider light and heat capable of 
being measured by extension, all of the light and heat 
that would fall on the surface of the earth between 
A and B would be equal to the light and heat that 
would fall on the surface between B and D; but from 
B to D is twice as far as from A to B; hence the light 
and heat, being spread over so much more surface, 
would lose a considerable portion of their power, and 
their direct effects could not be felt at all at the 
point D. 

Study the figure carefully, and you will see that 
the light and heat that the earth's surface receives are 
the most intense under the direct rays, and that their 
intensity rapidly decreases as you go north or south 
from the equator. If you compare the different areas, 
you will find that the 30 degrees around the pole 
receive but one-seventh of the lio;ht and heat that 
the northern hemisphere does. You can see what a 
wonderful effect " the moving to and fro of the direct 
rays of the sun between the tropics " has on the distri- 
bution of light and heat. You can also see why it is 
so much colder in northern or southern latitudes than 
it is in the tropical regions, where the rays of the sun 
are more nearly perpendicular to the surface of the 
earth. 



&$ LIGHT AND HEAT. 

The si me is true as you go east of west of the 
sun's meridian. This explains why the mornings and 
evenings are so much cooler than mid-day; and, if it 
were not for the rotation of the earth, a greater portion 
of its surface would become frigid, and we cannot 
imagine the intense cold of that portion directly oppo- 
site to the sun, while it would be equally difficult to 
tell what the effect under his direct rays would be. 

The slope of portions of the surface of the earth 
also affects the distribution of light and heat the same 
as its curvature does; so that large sections of land 
that have rivers running to the northward do not 
receive the same amount of light and heat as equal 
areas in the same latitude having rivers running 
toward the south. 

You have probably noticed that the snow on the 
south side of a roof begins to melt before the snow on 
the north side does. It is not because the sun does 
not shine upon both sides of the roof, but because 
both sides do not receive the same amount of sunlight, 
as the diagram on the following page will show. 

The slopes AB and BC represent the same extent 
of surface to be warmed by the sun, and the distances 
between the arrows A, B, and C, represent the relative 
amounts of heat that each side will receive. You can 
readily see that the southern slope will receive double 



EFFECT OF MOUNTAIN RANGES. 89 

that of the northern slope; but, when the sun moves 
northward, so that the rays will be in the direction of 
the dotted line DC, the amount of light and heat that 
strike the northern slope will be increased; and, if 
the sun should get into a position so that the point B 
would receive the direct rays, both sides would receive 
the same amount. 

/ / 

i 4 




u< — m 



In studying the globe, you will see that some of the 
countries have mountain ranges running east and west, 
and yon can see that they will have plains on either 
side whose slopes will correspond to the diagram we 
have just studied; and you can also see which side will 
be the warmer and why. 

Thus there are five things to be considered in 
studying the distribution of light and heat: (1) the 
distance of any place north or south from the equator; 
(2) the yearly revolution of the sun, which carries 
the direct rays north and south; (3) the rotation of 
the earth; (4) the slope of the land; and (5) last ; 



90 LIGHT AND HEAT. 

and most important of all, the winds and the ocean 
currents. 

In applying these principles to the study of the 
globe, it will be well to begin with the earth at one 
of the equinoxes, and then you can make use of the 
parallels of latitude in measuring distances and com- 
paring areas ; but, when the earth is at any other point 
of her orbit, you must keep in mind the direct rays of 
the sun. You must also remember to take into con- 
sideration the mountain chains and the river systems, 
as they will indicate the slope of the land, which will 
modify all other things to be considered. Begin at 
the poles with the earth in the position shown by the 
figure near the beginning of this chapter. The sun 
can just be seen at the horizon, and the rays of light 
are parallel to the surface of the earth, so that they 
do not make any angle at all, in other words, do not 
seem to touch the earth; but, as you move a little 
farther to the south, lines drawn from the sun to the 
earth's surface make a very sharp angle ; and, if you 
draw a line from the poles to the sun, and another 
parallel to it, from the 60th degree of latitude to the 
sun, they will not be very far apart ; but, if you will 
draw another parallel line from the 30th degree to the 
sun, it will be three times as far from the line drawn 
from the 60th degree, as the line drawn from the 60th 



APPLYING PRINCIPLES. 91 

is from the line drawn from the 90th degree, and the 
angles formed with the surface of the earth will rap- 
idly increase in size till you come to the equator, where 
the angle is 90 degrees. So, if 90 represents the 
maximum amount of light and heat received from the 
sun at the equator, it will be zero at the poles, and, for 
any place between the equator and the poles, it will 
be some number between zero and 90 that will cor- 
rectly represent the inclination of the sun's rays. 

It is a principle, that, if the temperature of air and 
water be increased, they will occupy more space, and 
have a greater power to resist the force of gravity. 
Hence they have a tendency to recede from the center 
of the earth, and, being perfectly mobile, they seek a 
position where this tendency is balanced by gravity. 
If the temperature of either be again increased, its 
position is again disturbed, and the same result follows. 
Of course, when these particles of air and water leave 
their original position, others take their places, and, in 
turn, become warmer, and give place for still others; so 
these elements can never be at rest, always having a 
tendency to follow each other, and currents of air or 
water are produced. As these currents carry with 
them the temperature of the places from whence they 
came, and gradually lose it as they come in contact 
with colder bodies, they become a distributing agency ; 



32 LIGHT AND HEAT. 

and warm winds may blow, or ocean currents carry, 
some of the warmth of southern climes to northern 
latitudes, as in the case of the Gulf Stream, which has 
such a wonderful eifect on the temperature of the 
coasts of England and Norway. So a change of wind 
usually means a change of temperature, and, if we 
lived on the seacoast, the ocean currents would bring 
to us the temperature of some distant point. These 
are important facts in the study of climate, which 
will be the subject of our next chapter. 



CHAPTER XIII. 



CLIMATE. 



The subject of climate is so closely related to the 
facts noted in the last chapter, that it merits some 
attention here, and the surface of a globe furnishes a 
splendid opportunity to study the theory of climate. 
By applying the facts in the last chapter, you can tell 
something of what the climate of any place is without 
knowing definitely beforehand. 

If it were not for the part that the winds and 
ocean currents take in distributing heat, the location of 
any place would determine its climate, for its tempera- 
ture would then depend upon conditions that are con- 
stant and uniform. To better understand this subject, 
it will be well to keep in mind the principal agencies 
that cause the distribution of light and heat, mentioned 
in the last chapter. Carefully determine which are 
constant, and which are not. There are variable con- 
ditions that will be considered here. 

If you should warm a large stone, it would take 

some time for it to acquire the same temperature as 

(93) 



94 CLIMATE. 

the heat applied, and it would remain hot for some 
time after the source from which it derived its heat 
had been removed. It would then gradually cool 
until it was of the same temperature as its surround- 
ings; and, the longer it took for it to absorb the 
heat that it had acquired, the longer it would take for 
it to part with it, and the more uniform would be the 
temperature of all contiguous objects, for, while 
cooling, it would impart its warmth to them. Also, 
the more rapid the diffusion of heat the greater will 
be the extremes of heat and cold when the source 
of the heat received is not constant, as in the case of 
the heat received by the earth from the sun. It is 
evident that the length of the days and nights is an 
important factor to be considered in this connection. 

The diffusion of heat is dependent upon the law 
of nature, that all bodies, in the presence of warmer 
bodies, will absorb a part of their heat, and, in the 
presence of colder bodies, will give up a part of their 
own heat. This greatly modifies other natural condi- 
tions ; and, as the tendency is constantly in the direction 
of maintaining an equilibrium, one change produces 
another until the whole is balanced, if that be possible. 

The oceans and the continents cannot be affected 
to the same extent by the sun's rays, because of the 
mobility of the particles of water, and the immobility 



CLIMATE AND SOIL. 95 

of the particles of which the earth's crust is composed. 
Then, too, these particles differ in kind, and some 
kinds receive heat more readily than others. Sand 
and muck exposed to the sun for the same length of 
time do not appear to be equally warm; for such badly 
conducting substances as sand convey, the heat pro- 
duced by the sun's rays downward, into the soil, with 
extreme slowness; hence it must remain longer on the 
surface, and in immediate contact with the air. This 
not only makes the surface of the ground much warmer 
during the day, but it permits the air passing over 
it during the night to rapidly absorb its heat. It is 
in accordance with this fact "that the climate of sandy 
deserts is characterized by nights of comparatively 
great cold." So, different kinds of soil have some- 
thing to do with the climate; for, where the soil 
gives up in a few hours all the heat it has acquired 
daring the day, the temperature becomes much lower 
during the latter part of the night; but, where the 
soil retains a part of its heat all night, the days and 
nights are more uniform in temperature. 

The heat that the earth receives from the sun does 
not penetrate below its surface to any great extent, 
only a few feet, even in tropical countries ; and this 
heat is constantly radiated, warming the air with 
which it comes in contact. The air also receives heat 



96 CLIMATE. 

from the sun's rays while they are passing through it. 
So the atmosphere receives heat in at least three ways: 
(a) directly from the sun; (b) by coming in contact 
with the heated surface of the earth ; (c) by absorbing 
the heat of reflected sunlight. 

At sun-down, two of these sources of heat are cut 
off; but, because of the radiation of the heat absorbed 
by the earth during the day, it does not get cold as 
soon as the sun is down, and the early evening hours 
are nearly as warm as just before sun-down. Heat 
continues to radiate all night, so that it would be 
colder just before sunrise than at any other time during 
the twenty-four hours, if all other conditions remained 
unchanged. 

After sunrise the temperature gradually increases. 
The heat that comes from the sun first evaporates the 
moisture that has accumulated daring the night, and 
then begins to warm the ground, which, in turn, warms 
the air; and it is its chief source of warmth, for the 
•sun's rays do not lose more than one-third of their 
heat \\ hile passing through the atmosphere, so the re- 
maining two-thirds must find its way back into the 
atmosphere by radiation and reflection. This is the 
reason why the lower strata of the atmosphere are so 
much warmer than the upper, also why it is frequent- 
ly so much warmer about 2 o'clock in the afternoon 



CLIMATE OF THE OCEAN. 07 

than at any other time during the day, if all other 
conditions have remained unchanged; for, though the 
direct heat of the sun decreases after it has passed the 
meridian, the earth continues to radiate the heat ac- 
cumulated during the afternoon, which adds its force 
to that of the sun's rays, this combined heat reaching 
its maximum about 2 o'clock. 

Where there are small hills and valleys, the hills 
will be warmer than the valleys; for the cold air, 
being heavier than the warm, finds its way into the 
lower levels, while the warm air ascends, and adds 
its heat to that of the hill-tops. 

The ocean is not subject to such sudden changes 
as the land ; for the heat received from the sun pene- 
trates it to a greater depth than it does the land, the 
solar rays affecting water to a depth of 500 feet. Their 
warmth is distributed through a comparatively thick 
layer, which it would not be possible to raise to the 
same temperature with the same amount of heat as it 
would the thin layer of earth that receives the heat of 
the sun ; it also requires double the amount of energy 
to warm water that it does to warm the materials of 
which the land is composed. If the surface of water 
is cooled in the least, it becomes heavier, and, b cause 
of the mobility of its particles, immediately settles, and 
the warmer particles from below take its place, so that 



98 CLIMATE. 

ordinarily no portion of a body of water will be 
warmer than its surface. Since, then, it is impossible 
for the ocean to acquire its temperature as easily as 
the land does, it must follow the general law, and 
retain it longer than the land. 

Heat stored up in any substance is called Latent 
Heat ; and, when liberated, it is called Sensible Heat, 
— that is, the heat that we feel. Water is a great 
store house for heat ; and, when it loses its heat till its 
temperature is reduced to 32 degrees Fahrenheit, it 
becomes solid ice. If the water is of the same temper- 
ature as your hand, it must give up a number of 
degrees of heat before it can freeze, and this heat 
would help to warm all bodies with which it came in 
contact. In this way ocean currents warm northern 
latitudes with the latent heat that they have stored 
up in the tropics. 

The ocean is a great modifier of the climate of all 
of its islands, and of the coasts of all countries border- 
ing upon it; but we must not forget that this surface 
water may come from the arctic regions as well as 
from the tropics, and that it may cool the surrounding 
country instead of warming it. So, in studying 
climate, we must first determine where the ocean 
current came from, and the red or blue lines on your 
globe will tell you ; but, whatever its source, it must 



OCEAN CURRENTS AND WINDS. 99 

be warmer than 32 degrees Fahrenheit, and, if the 
temperature of the surrounding country is lower than 
that, it will make it warmer. Although the Faroe 
Islands are in latitude 62 degrees, their inland waters 
never freeze, owing to the west winds and the sea. 

The influence of the ocean currents is always next 
to that of the winds ; but the ocean currents also help 
to either warm or cool the winds ; for instance, cold, 
deep sea currents rise to the surface just off the coast 
of northern California, and cause cold day winds at 
San Francisco. 

One other fact must be taken into consideration. 
Water, both on the sea and on the land, is being evap- 
orated by the sun's rays, and its vapors store up an 
immense amount of latent heat. These vapors are 
carried by the winds, and at last condense in the form 
of rain, and the latent heat is liberated. You can tell 
what the effect would be, both at the place where the 
vapors are formed, and where they are condensed. 

With all of these different factors at work, it seems 
as though there never could be the same kind of cli- 
mate from year to year ; but, if the weather for any 
locality be carefully observed for a long period of 
time, it will be found that it nearly repeats itself ; and, 
while the years are not exactly alike, some being hot 
and dry, and others with copious rains, still each 



100 CLIMATE. 

country has its own peculiar climate, and it changes 
but little from year to year. Its extremes of heat 
and cold may be very great, or its temperature and 
rainfall may be nearly uniform. 

Near the equator, there is no division of the sea- 
sons into summer and winter, for the variation of the 
temperature between day and night is greater than 
that between the different days of the year; but, no 
farther than 40 degrees from the equator, this variation 
may be very great, for in summer the temperature is 
sometimes 100 degrees in the shade, while in winter 
the thermometer has been known to fall to 30 degrees 
below zero, and, as a general rule, the farther from the 
equator, the lower the winter temperature. 

If you will take your globe and place the earth at 
midwinter's day, you will notice that the most northern 
rays of sunlight extend only to the polar circle; and, 
if you will measure the distance from Chicago to the 
polar circle, you will find it to be about 25 degrees. 
Then, if you will place the earth at midsummer's day, 
you will see that the north pole is 23^ degrees from 
the limit of sunlight, and farther from the direct rays 
of the sun than Chicago is on midwinter's day. So 
you can see that one acre of ground at Chicago will 
receive more light and heat on midwinter's day than 
an acre at the north pole receives on midsummer's 



LOCALITIES COMPARED. 101 

day; and then, taking into consideration the long win- 
ter night of the polar regions, and comparing with 
our winter, which must be warmer than their summer, 
you can better understand the intense cold of a winter 
within the arctic circle. 

Extensive areas of land must have a lower aver- 
age temperature than extensive areas of water having 
the same latitude, and places sheltered from cold 
winds must be warmer than places exposed to them. 
Places on different sides of mountain ranges often do 
not have the same climate. The mountain tops of 
these ranges may condense all of the moisture of the 
air, so that the plains on one side, at least, may be 
deprived of rainfall for a part or the whole of the 
year. Study the general directions of the winds, and 
the nearness of the mountains to the sea, and you can 
determine this feature of climate. 

With your globe and what is said above, answer 
the following questions, and see what your geography 
says about the climate of the places mentioned. How 
near can you determine it ? 



QUB3TIOIsrS OUST CIiTUUC-A-TIE. 

If you will look at the analemma on your Tellurian, you will notice 
that the sun is in the same latitude for a part of February as it is in 
October. Why is it not as warm in February in the northern hemi- 
sphere as it is in October? What part of this chapter tells why? 



102 CLIMATE. 

Cuba and the Sahara Desert have the same latitude. Would they 
naturally have the same kind of dimate? Tell what would naturally 
influence the climate of each place. (The arrows give the general 
direction of the wind.) 

In the western part of the United States is a large basin sur- 
rounded by mountains of considerable elevation. What would be their 
effect on the rainfall of this basin? What would you expect to find on 
the mountain tops? How would this affect the winds on the plains 
below? Would it affect the nature of the soil? The vegetation? 

Italy is nearly surrounded by water, and has the Alps on the north. 
How would this affect her climate? With the desert region at the 
south of the Mediterranean sea, and with mountain ranges running east 
and west in central Europe, how w T ould you expect the climate of 
southern Europe to correspond with that of the United States in the 
same latitude? W T hat are the climatic conditions of this portion of the 
United States? 

Would you expect the general temperature of South America would 
be warmer or colder than that of North America? Why? Which 
would be the more uniform? Why? 

Can you give any reason why England should have a warmer tem- 
perature than New York? Why it should be colder? Which of these 
conditions prevails? 

Which coast of the United States is the warmest? Why? What 
portions of the United States have most snow? Why? 

The following newspaper item is of interest, and 
will help you to better understand some of the weather 
changes that occur in the southern hemisphere while 
we are having our winter. You will notice that the 
time referred to was only a few days before our 
midwinter's day. The year was 1893. 



ZD-AJITS OIF 1 EXTBEMB KCIE-A-T. 

Suffering from Torrid Weather in New South Wales. 

Great heat prevailed in New South Wales early in December. On 
December 5 a northwest wind came like a scorching gust from an 
oven, and early in the forenoon, at Sydney, the thermometer rose to 90 



DAYS OF EXTREME HEAT. 103 

in the shade. By noon it was 936, or 54 degrees higher than the record 
for the year, and it continued at over 93 for fully 2 hours, and was over 
90 for three hours. The force of the wind rose from ten to twenty 
miles, and there was no escaping it. 

Again, on December 10th, a wave of heat swept over the colony; 
the recorded temperatures at many places are said to be higher than 
ever known. For forty-eight hours it blew from the northw T ard strai ht 
down from the tropics across the arid plains of the interior, until the 
heated air became quite unbearable for white people. At Euston, in the 
far southwest of the colony, it was 116 degrees in the shade, there being 
no recognized reliable method known to science for measuring what is 
known as " in the sun" temperature. The shade heat at Euston would, 
however, more than satisfy the ardent admirer of hot weather. Bal- 
ranald reported 111 in the shade: Bourke, 109; Braken Hill, 109, and 
Deniliquin, 110. Twenty-four stations report from 90 to 100, and tem- 
peratures from 89 to 90 were general. At Sydney the weather was 
extremely oppressive, but the temperature was not within 10 degrees 
of the heat recorded in the hot northwester of the previous week. 



CHAPTEK XIV. 



THE MOON. 



No object iii the heavens has attracted so much 
attention as the Moon and her mysteries, for the moon 
is so near, as compared with other heavenly bodies, 
that it has seemed as though she must give up her 
secrets. An object of beauty, "The Queen of Night," 
she has been the first of the "other worlds" to attract 
the attention of the child, and call forth its admiration 
and speculations ; and to know her history has been 
the dream of many an astronomer who would have 
given his remaining days if he could have shown the 
world what has transpired on her fair face since first 
her pilgrimage around the earth began. If the "Man 
in the Moon" would only tell his story, what audience 
of interested listeners would equal his? 

With the exception of a few days in each month, 
she stands guard over the sleeping world for a part of 
each night in the month. For a few days she retires 
from sight, and hides herself in the glare of the sun's 
rays, and then comes out with silvery crescent in the 

(104) 



THE MOON'S DAY AND NIGHT, 105 

western sky to begin her night watch again. And 
many the glance of love and admiration turned to 
this new moon. 

In Chapter VIII. I told you about the day and 
night on the moon, and now I want to tell you what 
must happen during that day and night; but first read 
again what is said in Chapter VIII. Note what is 
said about the pliases of the moon; that is, the new 
moon, the first quarter, the full moon, and the last 
quarter, or the old moon, as it is sometimes called. 
But these phases have nothing to do with what 
happens on the moon's surface, and that is what we 
want to consider now. 

All of the evidences known to science indicate the 
absence of any atmosphere around the moon, and there 
are no indications that there is any loater on her sur- 
face. With one of her days equal to about fourteen 
of ours, with no winds or ocean currents to distribute 
the heat, and without an atmosphere to absorb one- 
third of the warmth of the sun's rays, as is the case 
with the earth, imagination can form but a faint 
conception of what the heat of a lunar day must be. 
When we think of the temperature of our hottest 
summer days, and then think of that temperature 
augmented by the accumulations of fourteen days of 
constant glaring sunshine, we have the conditions that 



106 THE MOON. 

are supposed to exist on the surface of the moon 
during one of her days. 

The radiation of heat from the moon's surface 
can also go on more rapidly than is possible on the 
earth's surface. In the case of the earth, the air acts 
as a blanket, and tends to retard the radiation of the 
heat, while the absence of an atmosphere on the 
moon's surface permits radiation to go on rapidly, 
and heat is lost as fast as it has been acquired, and 
the opposite extreme will be the sure result. The 
temperature of the night will be as low as that of 
the day has been high. The intense cold of the long 
night, about fourteen of our days and nights, can only 
be compared with the winter season at the poles, 
unless there are other conditions, unlike those with 
which we are acquainted, to modify it, and that are 
quite opposite in their effects to nature's laws on this 
earth, which is not probable. This seems to settle the 
question of whether there is any life on the moon or 
not; but there may be forms of life and intelligence 
compatible with these conditions. We merely know 
that, with our present environments, the above condi- 
tions would result in the extinction of all of the forms 
of life with which we are familiar. 

We know, however, that life can be sustained 
under conditions that would be fatal to us. On our 



LIFE ON THE MOON. 107 

earth, life exists everywhere except in the midst of 
fire, and everywhere Nature has placed some form of 
life to be supported. " We know, that, in the strong 
acids that would instantly kill bird, beast, or fish 
placed within them, there exist and thrive minute 
creatures, adapted by nature to the strange conditions 
in which they are placed. Even in the bowels of the 
earth, and in the very neighborhood of active vol- 
canoes, we find the volcano-fish existing; in such 

7 o 

countless thousands, that, when they are from time to 
time vomited forth by the erupting mountain, their 
bodies are strewn over enormous regions, and, as they 
putrefy beneath the sun's rays, spread pestilence and 
disease among the inhabitants of the neighboring 
districts." So we cannot say that there are no forms 
of life on the moon, but can say that the conditions on 
the moon are such that we can only guess at the 
probable results. 

Notwithstanding the probable effect of the sun 
upon the temperature of the moon during the day, she 
is spoken of as the "frozen planet," also as the u de;id 
planet/' Without vegetation such as we have on our 
earth, and without life such as we know, the fair face 
of the moon can be but a dreary waste; still, in the 
economy of nature, she has probably held an impor- 
tant place and may be to-day as important as the 



108 THE MOON. 

earth, which, compared with the universe, is a mere 
point in the realm of the unknown. 

Our telescopes reveal the fact that there lias been 
volcanic action on the moon the same as there has 
been on the earth; that her surface is covered with 
the craters of extinct volcanoes, and that there are 
hills, valleys, and mountain ranges there, the same as 
here, wliicli indicates that at some time the moon has 
been subject to changes like those through which the 
earth has passed; but the question of what form of 
life existed there remains unanswered. 

The part that the moon takes in the economy of 
nature is a mystery. Many are the myths that have 
been told concerning her relations to the earth and to 
mankind; but men of learning, so far, have found out 
but few things about the moon of which they feel 
positive. They know that she is the cause of the 
eclipses of the sun, and that she is also the principal 
cause of Tidal Waves on large bodies of water. 

Tidal waves are caused by the force of gravity in 
its relation to the moon and the earth. They are 
also caused by the sun in the same manner as by the 
moon; but, owing to the comparative nearness of the 
moon, her influence is greater than that of the sun, 
and she causes much larger tidal waves than the sun 
does. The largest tidal waves occur when the sun and 



SPRING TIDE. 109 

moon appear at the same, point in the heavens, when 
their tidal waves unite, producing a wave equal to 
both that of the sun and that of the moon, and it is 
called the Spring Tide. This tide occurs twice each 
month, once when the moon is "new," and once when 
the moon is "full;" but, when the moon is full, the 
sun and the moon are at opposite, points in the 
heavens, and it is difficult to understand how their 
tides come together at this time. 

The force that causes tides is a constant one ; but 
it does not act equally at all points on the earth's sur- 
face at the same time, and but twice in the same place 
in each twenty-four hours with very nearly the same 
force. Of course, greater force is exerted on the 
moon's and on the sun's meridians, and this force is 
greater when they both are on the same meridian at 
the same time. The daily rotation of the earth on its 
axis brings the sun to the same meridian in about 
twenty-four hours ; but the moon does not come to the 
same meridian in that time, for the moon moves in an 
easterly direction in her orbit, at the rate of about 
thirteen degrees for each day; so that, in order to 
bring the same point on the earth's surface back again 
to the moon's meridian, it would require a little more 
than one revolution, enough more to equal the thirteen 



110 THE MOON. 

degrees that the moon has . moved in her orbit. It 
requires fifty-two minutes to do this ; hence the tides 
caused by the moon are fifty-two minutes later each 
day, while those caused by the sun occur at the same 
time daily. This would cause their tides to become 
separated, and they would get farther apart each day 
for the first week; while, during the second week, the 
tides caused by the sun would lessen this distance, and 
at the end of the week would overtake the tides 
caused by the moon. The moon would now be full, 
and spring tide would occur again. During the third 
week the tides would again separate, and at the end of 
the fourth week they would be together again. At 
the end of the first and the third week the tides are at 
their lowest point, and are called Neap tides. At this 
time the sun and the moon partially neutralize each 
other's tides on the earth, and the tide caused by each 
is diminished by the effect of the other, as will be 
shown on page 113. But to understand just how these 
tides are produced is not so easy, and especially how 
the sun or the moon can produce a tide on the 
opposite side of the earth as well as on the side 
that is under their direct influence. The following 
figure will be of assistance in studying into this 
matter: 



THEORY OF THE TIDES. Ill 




© 



It is not possible to get the proportions accurate 
in the figure; still, the outlines given will serve the 
purpose of illustration. M represents the moon, and 
O the center of the earth. The dark part represents 
the solid portions of the earth; the light part, within 
the dotted lines, represents a section of the Atlantic 
Ocean, and a section of the Pacific Ocean opposite 
to it, and A and B are opposite points in these 
sections, and in line with the center of the moon. 

No theory for the causes of the tides, yet pre- 
sented, is entirely satisfactory to the author; but the 
following is offered as a basis for discussion. 

The line of attraction between M and O must be 
greater than between M and any other portion of the 
earth's surface; so this would lessen the force of 
gravity at A, a point on the moon's meridian and on 
this line of attraction. Gravity being lessened at this 
point, the tendency would be for the mobile portions 
of the earth's surface to recede from the center of the 
earth, producing a long wave in the larger bodies of 



112 THE MOON. 

water. As the sun or moon advances, these waves 
follow. They are not like waves produced by the 
wind, however; for they are produced by strong 
currents, in which water is carried for long distances 
on the crest of the wave, and backward long distances 
in its trough. That tidal waves are caused by a less- 
ening of the force of gravity, is in harmony with the 
fact that water is affected throughout its entire depth, 
while other waves disturb water to only a small depth 
below the surface. 

The tidal wave at A, and the moon's attraction, 
would naturally move the center of gravity, O, 
nearer to A than the center of the earth is, and that in 
turn would lessen gravity at B, a point opposite from 
A.* The result would be a tidal wave at B, which 
would maintain an equilibrium of the earth in her 
daily rotation. These tidal waves are like the day 
and night hemisphere in their course around the earth, 
for it is the earth's rotation that carries them around 
her. 

When the moon is in quadrature the tides are at 
their lowest, for then the tides of the moon occur in 
the trough of the tides produced by the sun. The 
following figure will make clear what is meant by 

* Read the theory based on the revolution of the moon and the 
earth around their common center of gravity. 



CEESTS OF TIDAL WAVES. 113 

the crest and trough, the ebb and flood, of the tides: 






The arrow points in the direction of the rotation 
of the earth, and the direction of the tides would be 
just the opposite; that is, from east to west. The 
points A and E are at the crests of the tidal waves, 
and C is at their trough; D is at the ebb, or falling, 
of the tide, while B is at the flood, or the rising, of 
the tide. It is said to be high tide at A and at E. 
and low tide at C. 

Refer again to what is said on pages 109 and 110, 
keeping the above figure in mind. First consider 
spring tide at A, and then consider that it is a week 
later and that neap tide is at A. Under these con- 
ditions where would the sun's tide be? 

While the tides produced by the sun occur about 
twelve hours apart, those produced by the moon occur 
about fifty-two minutes later each day; so that, if the 
crest of the tide produced by both the sun and the 
moon, were at A, in a week's time the tide produced 
by the moon would have fallen behind to the point C, 
and would then be in the trough of the sun's tides. 
It would continue to fall behind again till it reached 
the point E, when it would be at the crest of the 



114 THE MOON. 

sun's tide again, and would produce a Spring Tide. 
When at C it is called Neap Tide. 

The shape of the coast lines of the oceans has a 
marked effect on the height of the tides, while in 
mid-ocean it is probably less than two feet and hardly 
noticeable. At the Bay of Fundy the tides rise to their 
greatest height on the globe, the Spring tide rising 
to a height of 50 feet, and the Neap tide 24 feet. In 
mid-ocean the highest point of the tides would follow 
a line drawn from the center of the moon to the 
center of the earth; but, when the crest of the tide 
reaches a coast line, the direction of the tide is 
changed, and takes the direction of the coast line. If 
you will take your globe and find the Bay of Fundy, 
you will notice that it is a long, V-shaped body of 
water, and that it opens into the ocean in such a way 
that it will catch the tide as it turns off from the coast 
of the New England States and goes north. The 
water becomes hemmed in as it approaches the point 
of the V, and the effect is the same as it would be 
if the current of a large stream of water should be 
stopped by a dam. 

When the tidal wave crosses the ocean from the 
east, and reaches the western coast, it is deflected 
from it, and takes the direction that offers the least 
resistance to its onward flow, as I have stated above. 



EBB TIDE. 115 

When it can turn in neither direction, it piles up on 
the coast line till the tidal influence has passed, and 
then flows backward, taking the name of Ebb Tide. 

We often hear of the "man in the moon," light 
and dark patches on the moon's disc, which are 
probably caused by irregularities of th-3 surface, and 
have caused a great many to imagine that the surface 
of the moon resembles a man's face. When the moon 
is in quadrature, she presents a beautiful appearance, 
and, when viewing it with a good telescope, these 
irregularities are quite distinct. 

Handed down to us with other myths that have 
found their way into every language, is the belief 
that the moon in some way affects the weather and 
the growing crops. It is not uncommon for some 
farmers to wait for a certain phase of the moon before 
planting seed, firmly believing that it is an impor- 
tant step in assuring an abundant harvest. They 
watch the new moon to see whether it is going to 
be wet or dry, without thinking, that, at nearly the 
same date of the previous year, the horns of the moon 
pointed in exactly the same direction as at the time 
when they are looking to see what the weather 
will be for the coming month. For them the new 
moon determines this all-important question. 

Before attempting to explain why the horns 



116 THE MOON. 

of the moon do not always point in the same 
direction when the moon is new, I want to call your 
attention to the figure on the following page, showing 
the nodes of the moon, and the inclination of the 
moon's orbit to that of the earth. 

No attempt has been made, in this figure, to 
get the exact proportion as regards distance. That 
would be impossible and have the size of the moon 
such as would show its crescent to advantage, and 
the figure as it is, will serve all purposes. The 
actual inclination of the moon's path to that of the 
sun is five degrees, while the angle at which the 
lines in the figure cut each other, is fifteen degrees; 
but the distances are so great, and the sun and moon 
so small in comparison with surrounding space, that 
the phenomena shown in the figure occur as repre- 
sented. The arrow at the right margin represents 
direction with reference to the earth's surface, and 
the dotted lines represent the paths of the earth and 
the moon as indicated. The star is at the moon's 
node, that is, the point where her path crosses the 
sun's path. Since the moon's revolution around the 
earth occurs once in twenty-nine days, she must 
cross the sun's apparent path twice during this 
time, and half of her journey is north, and half of 
it is south, of the sun's apparent path. The points 



z-«- 



r 

t 


i' 


V 


oc 


V 


<• 


i 


u* 


1 


1 

UJi 

Xi 

H 

i 


i 
I 


*■! 


tn» 


o! 


*\ 


i 


o\ 


XI 


Oi 


H 


1 


3 




NODES OF THE MOON. 
(117) 



US THE MOON. 

where the moon's path cuts the ecliptic (the sun's 
apparent path) are called Nodes. The node where 
the moon passes from the south to the north side 
of the ecliptic, is called the Ascending Node, and the 
opposite node is the Descending Node. 

If the new moon occurs while she is in her 
ascending node, the horns will be in the direction 
that they are when the moon is at A; but, if the 
new moon occurs when she has passed her descend- 
ing node, the horns will point in the direction that 
they do in B ; the horns always pointing in directly 
the opposite direction to that of the sun from the 
moon. So, by looking at the moon, you can tell the 
direction of the sun from her, no matter at w r hat 
time of the night you look. When she is south 
of the sun's path her horns will point downward; 
and, when she is north of the sun's path, they will 
point upward. These phases of the moon are called 
the wet and the dry moon. I think that the moon in 
the ascending node is called the dry moon ; for I can 
remember, when a little boy, of hearing my father say, 
"The old Indian could hang his powder horn on the 
moon to-night, and it wouldn't slip off, and I guess 
that we won't have much rain this month;" and my 
good old grandmother used to say, " that the horns of 
the moon point upward, and that will hold all the water 



POSITION OF THE CRESCENT. 119 

in the hollow, so the earth will go dry this month." 
S marks the position of the sun, and the lines 
drawn through A and B show the direction of rays of 
light falling upon the moon. Of course, the side of 
the moon that is toward the sun is the part that will 
shine, and we can see only a small crescent-shaped 
strip of that part. A line drawn through the points 
of that strip will pass through the center of the moon, 
and be at right angles to the rays of light that come 
from the sun. When looking at the moon, draw 
imaginary lines as I have them in the figure, and it 
will help you to locate the sun, and tell you whether 
the moon is in her ascending or descending node; 
that is, whether she is north or south of the sun's 
apparent path. The latitude of the observer will 
make a large difference in the direction of the points 
of the crescent. If you will look at the moon, some 
time, at about 3 o'clock in the morning, you will be 
surprised at the direction in which she indicates the 
sun to be. There is another interesting thing about 
the moon that I want to call your attention to before 
closing this chapter. 

You have probably noticed, that, at some times of 
the year, when you are on the moon's meridian, she 
appears to be much nearer to the southern horizon 
than at others, and that in the winter season the moon 



£83 THE MOON, 

is almost over otir heads when we are on her meridian. 
I can remember the old weather prophet saying: "The 
moon runs high to-night; look out for cold." Well, 
that is true too, for the moon never "runs high" 
except in midwinter, as you can see by looking at 
your globe, and a clear midwinter's night is pretty 
sure to be cold in this latitude. 

Place your globe at midwinter's day, and fix the 
moon so that it will be directly opposite to the sun. 
Rotate the globe so that Chicago will be on the 
sun's meridian, and notice the angle that a line drawn 
from Chicago to the center of the sun will make. 
Then rotate so that Chicago will be on the moon's 
meridian, and draw a line from Chicago to the center 
of the moon, and notice that this angle is not so great 
as the other; that is, that the moon is more nearly 
overhead, and "runs high." Place your globe on mid- 
summer's day, and try the same experiment. Remem- 
ber that the moon can never get more than five 
degrees farther north than the sun, and that she can- 
not go more than five degrees farther south than the 
sun's path; so she will appear sometimes nearer the 
southern horizon than the sun ever does; and, when 
the sun is nearest to the southern horizon, the moon 
is the nearest to the zenith ; that is, when the moon 
is full. Keeping in mind that the paths of the sun 



HIGH AND LOW MOON. 121 

and moon are never more than five degrees apart, this 
apparent difference will be, to you, one of the best 
proofs of the inclination of the earth's axis to her 
orbit ; for you are in the same relative position to the 
moon on midwinter's day that you are to the sun on 
midsummer's day, if you but make allowance for 
the angle of five degrees that denotes the moon's 
inclination. 

Observation will make you familiar with all that I 
have said about the phases of the moon, the "wet" 
and the "dry 75 moon, the "high" and the "low" 
moon, and the moon's nodes. You will not need 
instruments for this work. Observation of the moon 
will also assist you in locating most of the planets 
in our solar system, and will help you in recognizing 
them by name. Get an Ayer's Almanac, and study 
carefully the characters that represent the different 
planets and their positions in relation to the earth, 
the sun, and the moon. I have before me their 1894 
almanac (see "Appendix"), and make the following 
observations regarding the month of January. On 
the 3d of the month I find that Mars is in conjunction 
with the moon; so, by looking at the moon on that 
date, I shall see Mars near her, and two days later 
Mercury will be the nearest planet to the moon. 
Now, in two days, the moon has traveled twenty -six 



122 THE MOON. 

degrees in her orbit, hence Mercury and Mars are 
about 26 degrees apart at this date; and, by watching 
them from time to time, I will see that this relative 
position will change. The moon is also at her most 
distant point from the earth at this date. 

On the 10th, the moon is in conjunction with 
Venus ; and at this time Venus is at her nearest point 
to the earth, which would cause her brilliancy to be 
at its greatest. On a clear night the star and the 
crescent in the western sky are a beautiful sight. 

On the 13th, the moon begins her ascending node, 
and on the 16th is in conjunction with Jupiter, one 
of the most interesting planets in the heavens. J On 
the 17th she is in conjunction with Neptune; so 
Jupiter and Neptune are about 13 degrees apart on 
this date. On the 19th the moon has reached the 
most northern point in her ascending node, and is 
the nearest to the earth that she gets. She does not 
overtake any more of the planets until the 27th, 
when she is in conjunction with Saturn, and on the 
31st has completed her orbit and is in conjunction 
with Mars again. So, in making her circuit of the 
heavens, she has passed all of the planets, and you 
can get their names by watching for her conjunction 
with them. 

You probably noticed that she began her descend- 



, ECLIPSES. 123 

ing node on the 26th, and, of course, her different 
phases have not escaped your attention. You will 
notice that in March and August the moon is nearer 
to her ascending node when new, and to her descend- 
ing node when full, than at any other time during 
the year. These are the conditions necessary for 
eclipses, which we will study in another chapter. 
Notice how the time of the new moon and the ascend- 
ing node vary from month to month. The same is 
true of the full moon and the ascending node. 

You will see, that, by a little observation, you 
can become quite well acquainted with the heavens, 
and it will be with pleasure and interest that you 
will watch the ever-changing positions of the moon 
and the planets. You will feel that you are in closer 
communion with the mysteries that surround you, 
and in some way you cannot help feeling that you 
are a part of some plan that is being worked out by 
a Power that you seem conscious of, but can but 
very imperfectly know under present conditions. 
We can only stand between the two eternities, and 
wonder at the immensity of the problem before us, 
and feel, that, in some way, we must take part in its 
solution. 

Let us see what we can gather from the sun. 



CHAPTER XV. 

THE SUN. 

The Sun is the center of the solar system, around 
which the earth and all of the other planets revolve. 
He has an atmosphere, and is composed of the same 
kind of materials as the earth and all of the other 
planets that revolve around him; in fact, the earth 
and all of the other planets are supposed to have 
once been a part of the sun, and to have been evolved 
from his surface from time to time, in the order of 
their distance from him, One cannot imagine the 
immensity of the sun before any of the planets were 
detached; for his size at the present time is beyond 
our comprehension, his diameter being estimated at 
852,584 miles,* while that of the earth is a little less 
than 8,000 miles, his volume exceeds that of the 
earth by 1,245,126 times, and there is enough mat- 
ter in the sun to make over twelve hundred thousand 
worlds like ours. 

His distance from the earth is 91,430,220 miles, 

* These figures are given in round numbers. Different texts do 
not agree on the exact numbers. 

(124) 



THE SUN'S SPOTS. 125 

and, to the naked eye ; he appears only as a lumi- 
nous mass of intense and uniform brightness, giving 
both light and heat to the solar system. 

Before the evolution of any of the planets, the 
entire substance of the sun is supposed to have 
occupied all the space included in the orbit of his 
most distant planet, and to have appeared in the 
heavens as a nebulous cloud, perhaps as the nebula 
in Orion appears when viewed with a telescope. 
This nebula is one of the most beautiful objects in 
the heavens. 

There are many things about the sun that afford 
subjects for speculation, and one of them is the spots 
that appear on his surface from time to time. By 
carefully observing them for a long period of time, 
it has been determined that the sun rotates on his 
axis once in twenty-five of our days. The cause of 
the spots on the sun has not been determined, and 
a satisfactory description of them cannot be given 
in a book like this. They vary from time to time, 
both in number and size; but there is seldom a time 
when, by the aid of a telescope, they are not to be 
seen, and in some years they can be seen every day. 
In 1860, there was not a day when there were no 
spots on the sun's disc, and during the year 211 
different groups appeared, while in 1867 there were 



126 THE SUN, 

195 days that the sun's face was without a blemish. 

The spectroscope has told wonderful stories con- 
cerning the sun ; and you will be well paid to find 
out what this wonderful instrument is, and how it 
has been able to tell so much about the sun and the 
stars. What it has told verifies what had already 
been supposed to be true; that is, that the earth is 
composed of the same kind of materials as the sun, 
and that the sun is so intensely hot that it is capable 
of supporting iron, copper, and some of the other 
metals in the solar atmosphere, just as water is sup- 
ported in the atmosphere of the earth. At some time 
the sun will get cool enough so that these metals 
will be precipitated the same as rain is precipitated 
on the earth. Geology teaches that the earth has 
passed through just such a stage of development ; that 
at some time the materials that now compose the 
earth's crust were held by heat in suspension just as 
the clouds are; and that, when sufficient heat had 
been radiated into space, these materials descended 
just as the rain does now, and that the changes that 
have gone on since have been more or less dependent 
on the radiation of heat into space. What ulti- 
mately becomes of the heat is an interesting question, 
and one that will afford ample room for study. 

The spectroscope also tells us that the sun is com- 



SOLAR SYSTEMS. 127 

posed of the same kind of materials as the stars ; and 
our earth being made from these materials also tells 
us that we live on one of many worlds that form the 
universe, and that we, as a part, bear some mysterious 
relation to the whole. But, so far as we can tell, the 
same conditions do not exist on any of the other 
worlds that we have on ours; and, if the theory of 
the formation of the earth is correct, we know that 
there are many worlds that have conditions far dif- 
ferent from ours; and, while we cannot help thinking 
that they support some form of life, we cannot help 
wondering what that form of life may be. That so 
many worlds should be created without purpose, or 
that they came by chance, is not to be thought of 
for a moment. That all should be made to serve the 
purpose of one small world, our earth, seems almost 
absurd; for it is impossible for us to comprehend 
how even the nearest planet of our system can be 
necessary to our existence, or how it can in any way 
serve us, except as a thing of beauty, — one of the 
gems of the night. We cannot even tell the object 
of the creation of our own world. 

The stars, being in the same condition as the 
sun, cannot support forms of life such as we know ; 
but, like the sun, they may be centers of systems of 
planets like ours, peopled with beings like ourselves. 



128 THE SUN. 

This seems more than probable ; for, being alike in so 
many respects, they must, in some way, contribute to 
the evolution of a higher form of consciousness than 
that which we know, and to which we hope to attain. 

When we think that the sun is radiating into 
space, in all directions, light and heat, and then think 
what a small amount, compared with the whole, 
reaches any of the planets, we cannot help but 
wonder at the seeming waste of energy, and the in- 
quiry naturally arises as to what becomes of it. 
Is it distributed to every point of the universe? 
Will the sun continue to lose his heat until, at some 
time in the eternity to come, he will become like our 
moon, — frozen, — and be the center of dead and silent 
worlds, which, wearied by their ceaseless flight of 
countless ages, stumble from the paths they have so 
long followed, and rush together, returning to Chaos, 
whence they came? Will they form new worlds 
again ? 

The subject of light and heat is one full of 
interest, and one concerning which there has been 
much speculation. What is light? What is heat? 
We mi^ht say that light is that peculiar form of 
energy that is recognized only by the visual organs; 
but that gives no idea of what light really is. The 
undulatory theory of light is the accepted explana- 



LIGHT. 120 

tion of this phenomenon; that is, it is a mode of 
motion produced by luminous bodies ; but is the 
question answered? 

I have said that the sun is the source of all light ; 
but I am not so sure of that after all, for one of the 
most effective forms of artificial light with which we 
are acquainted, cannot be traced directly to sunshine 
in any form. I refer to the light that is produced 
directly by electricity, and electricity has so far 
refused to give up the secret of its origin. We know 
how to make its presence known, and can force it 
to serye us in many ways, but what is it? The 
undulatory theory of light must include light pro- 
duced by electricity as well as direct sunlight. 

Light, according to the undulatory theory, consists 
of a wave-like motion that is recognized by the visual 
organs only, and is produced by the bodies that are 
called luminous. Through the sensation of light we 
become aware of the existence of bodies with which 
we are not in actual contact, and the sensation that 
they produce is called color. Different colors are 
said to be produced by different wave-lengths; and 
the wave-lengths that can produce the sensation of 
vision are bounded on one side by the red, and on the 
other by the violet, rays of light. The wave-length of 
the extreme red is said to be twice that of tli 3 extreme 



130 THE SUN. 

violet; and between the red and violet are the wave- 
lengths that produce orange, yellow, green, blue, and 
indigo, which, with the first two mentioned, are called 
the colors of the spectrum. When mingled in the 
proportions that nature gives them, they form white 
light, by which is meant colorless light. 

Outside of this spectrum, Wave-lengths are known 
to exist, for science has been able to locate, by 
means of photography, stars that the telescope could 
not reveal ; because, while they did not have the 
power to produce any sensation on the visual organs, 
still they produced the chemical effect necessary in 
photography. The existence of rays having wave- 
lengths twenty times that of red rays has been found 
in the radiations of the moon. 

The difference between light and heat is a differ- 
ence of wave-lengths only; and both, probably, are 
forms of the same energy of which electricity is a 
near relative. If ail of these various wave-lengths 
could produce the sensation of vision, what wonders 
might be revealed to us ! 

But it is useless to follow this line further; for, 
while this theory has borne much good fruit, and 
while it answers more of the questions concerning 
light and heat than any other that has so far been 
offered, it is probable that science will gather a better 



CENTERS OF SYSTEMS. 131 

knowledge of this subject than we have at present, 
and that new fields of thought will be opened. 

In closing this chapter, we can feel assured that 
the place our sun occupies in the universe is that 
of a star, that in all probability the stars are centers 
of solar systems like our own, and that their destinies 
are subject to the same course of natural events. 
Nature has not yet seen fit to give up her secret, 
and she will hold her own counsel till that point 
in the evolution of consciousness has been reached, 
where she can share the wealth she has in store 
with those who thirst for the truth, and have been 
willing to delve deep for the hidden treasures that 
are to be found in the storehouse of knowledge. 



CHAPTEK XVI. 

ECLIPSES. 

It sometimes happens that the earth, the sun, and 
the moon get into such a position that their centers 
are in direct line; and, when this occurs, there is an 
eclipse either of the sun or of the moon. This occurs 
twice each year ; that is, they get near enough in 
line to produce partial eclipses. But, before going 
farther into the subject, I want to give you some 
diagrams showing the relative sizes of the earth, sun, 
and moon, so that you can better understand the 
length of the shadow that is made by the earth and 
the moon. 





Fig. 1. Fig. 2. 

(132) 



SUN, MOON AND EARTH. 133 

Fig. 1 represents the moon's orbit, and Fig. 2 
the size of the sun; while the small black spot in 
the center of the moon's orbit, is larger than would 
correctly represent the size of the earth if drawn on 
the same scale as the sun and the moon's orbit. 
It would take sixty worlds like the earth, touching 
each other, to span the moon's orbit.; yet, as you can 
see, this orbit is much smaller than the sun. The 
following figures represent the earth and the moon, 
drawn to the same scale: 



o 




Fig. 3. Fig. 4. 

Fig. 3 represents the size of the moon, and Fig. 
4 the size of the earth, drawn to the same scale. 
Fig. 4 and Fig. 2 are of about the same size, but they 
are not drawn to the same scale. If they were, Fig. 4 
would not be so large as the small black dot in Fig. 1 
and the moon (Fig. 3) would be hardly large enough 
to be seen. It does not seem possible that there is 



134 ECLIPSES. 

such a difference in the sizes of the earth, the sun, and 
the moon ; but such are the facts, as shown by the 
number of miles that measure their various diameters, 
and the preceding diagrams may give a better impres- 
sion of these facts than the numbers would. 

It will be impossible to make a diagram that will 
give the relative sizes, and at the same time give the 
relative distances, of the earth and the sun ; but we 
give the following illustration, representing the moon's 
orbit, and the relative length of the earth's shadow, 
also the direction of the sun's rays. A careful study 
of this illustration will tell you why eclipses do not 
occur each time that the sun and the moon are in 
conjunction or in opposition. 



c 




Fig. 5. 
The large circle represents the moon's orbit, and 
the arrow indicates the direction that the moon takes 



THE NODES. 135 

in her revolution around the earth, also the direction 
that the earth rotates on her axis. The points A and 
D are the moon's nodes. The point A is called the 
ascending node, and the point D the descending node. 
The line beginning at C and running through the 
earth, O, is in the same plane as the moon's orbit. It 
is drawn at an angle of five degrees to the plane of 
the ecliptic, and the moon's orbit intersects the plane 
of the ecliptic at the points A and D. The earth's 
shadow, which terminates at B, is always in the plane 
of the ecliptic, which is at an angle of five degrees 
to the moon's orbit. Suppose that the page upon 
which this is printed represented the plane of the 
ecliptic; then the moon's orbit would be inclined to 
the page at an angle of five degrees, and would pass 
through the paper at the points A and D. The point 
C would be on the other side of the paper, and the 
line beginning at the point would pass through the 
paper at the point O, and would continue on this side 
of the paper, passing through a point on the moon's 
orbit five degrees from the point A. 

The little dot at D is really larger than the moon 
would be, drawn to the same scale that the earth 
and the orbit of the moon are; but it represents the 
moon in this figure. You can see that she is just 
entering her descending node. When she reaches her 



136 ECLIPSES. 

ascending node, her shadow, which begins at A, will 
extend toward the earth; but it may not be long 
enough to reach as far as the earth is from the moon ; 
for, when the moon is at her most distant point from 
the earth, her shadow is not long enough to pass half 
across her orbit. Sometimes the moon is 251,947 
miles from the earth, her nearest point to the earth is 
225,719 miles, and her shadow varies in length from 
221,148 miles to 252,638 miles. 

Now, in the revolution of the earth around the 
sun, the shadow of the earth is always in a line 
which, if extended, would pass through the sun ; and 
this shadow lies entirely outside of the plane of the 
moon's orbit, except twice each year, but it is always 
in the plane of the ecliptic. If you will imagine the. 
point A moving around in the moon's orbit, you will 
see the general direction that her shadow will take ; 
and you will see that an eclipse cannot happen until 
the earth, in her revolution around the sun, reaches 
a point that shall be very near to the plane of the 
moon's orbit. Then, when the sun and the moon are 
in conjunction or opposition, an eclipse is liable to 
occur; for then the centers of the earth, the sun, and 
the moon, are nearly in line. If they are in con- 
junction, the eclipse will be that of the sun, and its 
character will be determined by their nearness to the 



ECLIPSES OF THE SUN. 137 

nodes and the moon's distance from the earth. If 
they are in opposition, the eclipse will be that of 
the moon, and its character will also depend upon the 
nearness of the sun and moon to the moon's nodes. 
We will first study the eclipses of the sun; and, 
of course, the sun and the moon must be in con- 
junction. We will also consider that they are very 
near the node, and that the moon's shadow will fall 
on the earth. If she is nearing her ascending node, 
her shadow will sweep across the south polar region; 
but, if she is nearing her descending node, her 
shadow will sweep across the north polar region. 
The nearer the node the conjunction occurs, the 
nearer the equatorial regions the field of the eclipse 
will be. If the observer is in this region, he will 
see an eclipse of the sun; and, if he is so fortunate 
as to be in a direct line drawn through the centers 
of the moon and of the sun, and the moon is at her 
nearest point in her orbit to the earth, the moon will 
appear to be as large as the sun, and there will be 
a total eclipse; that is, no portion of the sun will be 
in sight. But, if the moon is at the most distant 
pant in her orbit from the earth, and the observer 
is at the point mentioned above, a narrow rim of 
the sun will appear to encircle the moon, and it will 
then be called an annular eclipse of the sun. If the 



138 



ECLIPSES. 



observer is not in the direct line of their centers, 
but is in the field of the eclipse, the moon will pass 
over only a part of the sun's disc, and there will 
be a partial eclipse of the sun. A total eclipse of 
the sun is visible on only a small portion of the 
surface of the earth, while a partial eclipse is visible 
on a larger portion, as can readily be seen by an 
examination o? the following figure, which gives the 
relative sizes of the earth and the moon, and will 
also show how eclipses occur: 

Earth 




Fig. 6. 

If the sun and the moon followed the same path 
in the heavens, there would be an eclipse every month ; 
but the moon's path in the heavens is inclined about 
five degrees to that of the sun, and their distance from 
the earth is so great that they must be near the point 
where their paths cross < ach other in order to produce 



THE MOON'S NODES. 139 

an eclipse. Their paths cross at opposite points of 
the heavens, called the moon's nodes. The moon 
passes these nodes twice each month,— once when it 
is new, and once when it is full; but only twice dur- 
ing the year is the sun near enough to these nodes 
when the moon passes them to produce an eclipse of 
either the sun or the moon. 

In the preceding figure, the shaded spot on the 
earth represents a region where a total eclipse of the 
sun, indicated in the figure, is visible. The observer 
at A is looking in the direction of the arrow, from 
that point toward the sun, and the moon is directly in 
the path of his vision, so that the sun is not visible, but 
is hidden behind the moon, and the observer is really 
looking at the night hemisphere of the moon. The 
sun is at the moon's node; but she advances so rapidly 
in her orbit that it is rarely more than five or six 
minutes that the sun remains entirely hidden, and 
sometimes a total eclipse lasts only a few seconds, and 
is visible to only a small strip of country; but the 
time from the first apparent contact of the moon with 
the sun until the sun's disc is entirely uncovered is 
from two to three hours, and the region of country 
in which the partial eclipse is visible is quite exten- 
sive. The arrow B indicates a locality in such a 



140 ECLIPSES. 

region, and at this place tbe sun would appear some- 
thing like this: 




Fig. 7. 

An eclipse of the moon occurs when the sun is 
near one of the moon's nodes, and the moon is at the 
other. This would bring the moon in the shadow of 
the earth, which would darken a part or the whole 
of her disc. Eclipses of the moon can occur only 
when she is full, and the kind of eclipse depends upon 
whether she is at the nearest point in her orbit to the 
earth, or whether she is at one node at the same time 
that the sun is at the other. 

Fig. 7 will illustrate the appearance of the sun 
during a partial eclipse. A total eclipse cannot be 
represented by a picture that will give a very good 
idea of how it really looks, and, for that matter, no 
picture of an eclipse is a good representation of how 
it really appears. Fig. 8 will give you an idea of an 
annular eclipse. 

The ring shown in the figure cannot be perfect 



A TOTAL ECLIPSE. 



141 




Fig. 8. 

more than a few minutes, for the moon moves across 
the sun's disc in an hour or two. In order to make 
a perfect ring, the center of the moon must pass 
along the sun's diameter. The ring will be perfect 
when a line drawn from the point of observation will 
pass through the center of the moon and the center 
of the sun. 

We will now see what is liable to happen when 
the sun and the moon are in opposition, which will 
occur about two weeks after an eclipse of the sun. 
I should have stated that an eclipse of the sun can 
occur only when the moon, at the time of her con- 
junction with the sun, is within 19f degrees of her 
node, and will certainly occur when she is within 13£ 
degrees of her node. An eclipse of the moon can 
only happen when she is within 13^ degrees of her 
node at the time of her opposition with the sun, 
and must occur if she is within 7 degrees of her node 



142 ECLIPSES. 

at that time. If you could be on the surface of the 
inoon at the time of her eclipse and should look at 
the sun, the earth would seem to get between you and 
the sun, and there would be an eclipse of the sun. 
It would look just the same as it does when viewed 
from the earth; but an observer on the earth's surface, 
watching the same point on the moon at the same 
time, would see the moon entering the earth's shad- 
ow, which extends more than three times farther 
from the earth than the distance to the moon. Of 
course you will remember that the moon is full, and 
that her diameter is 2,160 miles, and that she may 
not be near enough to her node to permit more than 
four or five hundred miles of her diameter to pass 
through the earth's shadow. She would then appear 
like Fig. 7. If the moon should happen to be exactly 
at her node at the time of the full moon, a total 
eclipse would occur; that is, the entire surface of the 
moon would enter the earth's shadow; but the moon 
moves so fast in her orbit that its duration would be 
for a short time only. 

This year, 1894, there are four eclipses,— two of 
the moon, and two of the sun. The first is a partial 
eclipse of the moon, the 21st of March. It is visible, 
more or less, to the extreme western portion of North 
America, Asia, Australia and the Pacific Ocean. 



A PARTIAL ECLIPSE. 143 

About two weeks later, the 6th of April, there 
is an eclipse of the sun, visible only to eastern Europe 
and Asia. It is an annular eclipse. 

The next season of eclipses is in September, and 
on the 14th and 15th there is another partial eclipse 
of the moon, visible to North and South America, 
the western portions of Europe and Africa, and the 
Atlantic and eastern portion of the Pacific Ocean. 
Two weeks later there is a total eclipse of the sun 
visible only to portions of Africa, Hindostan, Aus- 
tralia and to the Indian Ocean. 

If you thoroughly understand all that has been 
said in this chapter, you can answer the following 
questions. Some of them can be answered by care- 
fully remembering what has been said in the text; 
but, to answer all, you will be obliged to use your 
imagination, and you can get some valuable assist- 
ance by the aid of your Tellurian. 

(STJBSTIOUS. 

1. Is the moon in her ascending or descending node at the time of 
the first eclipse? 

2. If she had been exactly at her node, what would have happened? 
Is she at her farthest limit from her node, or near the node? 

3. Can you tell about what time of day it is by the location of the 
territory in which the eclipse is visible? Can yon tell, by the extent of 
this territory, about how long it took the moon to pass the earth's 
shadow ? 

4. What would have been the necessary conditions for this eclipse 
to have been visible in the entire United States? For it to have been 
seen in South America? 



144 ECLIPSES. 

5. In the eclipse of the sun, is the moon at her nearest or most 
distant point in her orbit from the earth? What would have made this 
a total eclipse? 

6. In what node is the moon at this time? Can you tell the time of 
day that this eclipse occurs? 

7. At what time of day does the second eclipse of the moon occur? 
Will the shadow first appear on the northern or the southern limb of 
the moon? (Limb means the border or edge of the disc of a heavenly 
body.) 

8. Can you tell anything about what time it is in the United 
States when the last eclipse of the sun occurs? Which of the above 
questions will apply to this eclipse? 

With an 1894 almanac you can tell how nearly 
correctly you have answered these questions. You 
will probably need one to answer the last question, 
but you should be able to answer many of them 
with the aid of the Tellurian. 

In the next chapter we shall take up the dis- 
cussion of time. 






CHAPTER XVII. 



THE CALENDAR. 



We have seen that the rotation of the earth on 
its axis, causing day and night, makes a natural 
division of time. The revolution of the earth around 
the sun makes another natural division of time that 
has served the purpose of fixing the dates of events 
for ages. It seems probable that the- need of some 
exact method of reckoning time first gave rise to the 
study of astronomy, and called attention to the move- 
ments of the planets. 

The revolution of the moon around the earth has 
also served to help keep a record of time, each lunation 
having been called a month, until the establishment 
of the Julian Calendar, and twelve lunar months 
still make a year with the Mohammedans. But the 
revolution of the moon around the earth is not an 
exact measure of the revolution of the earth around 
the sun; so the year has been made the basis of 
reckoning time; and, in order to make the twelve 
months an exact measure of the year, various changes 

(145) 



146 THE CALENDAR. 

have been made in the number of days that should 
make the different months. Instead of being of the 
same length as the old lunar month of thirty days, a 
day has been added to a part of them, and two days 
taken from one of them, except in leap year, when 
only one day is taken from this old lunar month; 
or, as we say now in leap years, we add one day to 
February. 

Oar calendar, which is called the Gregorian 
Calendar because of certain changes that are made 
according to the directions of Pope Gregory XIII., is 
in general use, except in Russia, where the old Julian 
calendar is still used. It is but little changed from 
the Julian, the most important change being that of 
dropping the leap year from the centuries that are not 
exactly divisible by four; for instance, 1700, 1800, 
and 1900. The average calendar year is still a few 
seconds longer than the tropical year; but this will 
not make a day's difference till over 4,000 years have 
passed. 

The tropical year is 365 days 5 hours 48 minutes 
and 49.7 seconds. You will notice, with the aid of 
your Tellurian, that, in each year, the earth makes 
one more revolution on its axis than the number of 
days in a year, making a little more than one revo- 
lution each day on account of its onward motion in 



THE DOMINICAL LETTER. 147 

its orbit around the sun. You will notice, too, that, 
owing to the distance traveled by the moon in her 
orbit each day, it takes more than twenty-four hours 
for the same meridian on the earth's surface to return 
to the moon's meridian. 

The number of days in the week does not seem 
to have an exact relation to any of the other divis- 
ions of time; but the weeks seem to be, in their 
nature, religious divisions^ and were probably estab- 
lished to meet the religious requirements of man. 

The Dominical Letter, the letter of the alphabet 
that denotes Sunday, probably has a history that dates 
back to some religious rites for its origin. The days 
of the week and other divisions of time, and the 
dominical letter seem to bear a strange relation to 
each other, that, without their history, is not easy to 
understand. The following couplet, with the methods 
of calculation described in the rule and problems, 
will give the day of the week upon which any event 
happened if the date is known: 



Jan. 


Feb. 


March 




April 


May 


June 


A 


D 


D 




G 


B 


E 


July 


Aug. 


Sept. 




Oct. 


Nov. 


Dec. 


G 


C 


F 




A 


D 


F 




A B 


C 


D 


E 


F G 






1 2 


3 


i 


5 


6 7 





148 THE CALENDAR. 

The following mnemonic will assist you in remem- 
bering the couplet by using the first letter of each 
word: 

At Dover Dwells George Brown Esquire, 
Good Carlos Finch, and David Friar. 

Gr is the dominical letter for 1894, as found by 
following the directions given in the rule below : 

I. To the number of years above centuries add 
their one-fourth (omitting fraction), plus 2.* 

II. Divide this sum by 7. If there be a remainder, 
subtract it from 7, and the result will be the number 
of the dominical letter. If there be no remainder, the 
number of the dominical letter will be 7. 

III. In the foregoing couplet, the letters above the 
line represent the months. A is January, D is Febru- 
ary, D is March, G is April, etc. The letters below 
the line represent the days of the week, the dominical 
letter being Sunday. The figures are the numbers 
obtained in the solution of problems for finding days 
of the week from dates. 

IV. Begin with the dominical letter, calling it 
Sunday, the next to the right Monday, and so on till 
you come to the letter corresponding to the letter that 
represents the month given in the "date" required, 
and the day of the week represented by this letter 

* For January and February of leap years add I, 



PROBLEMS. 149 

will be the first day of the month. (See correction for 
leap years, given with one of the following problems. 

PROBIiBMS. 

1. Find on what day of the week May 28th, 1894, occurs ; also on 
what day of the week were January 16th, 1892, and March 5th, 1892. 

SOLUTION. 

(a) Years above centuries, 94 

(b) Their J£, the remainder not being considered, 23 

(c) Plus 2 

119 
The sum 119, divided by 7, equals 17 with no remainder. Then 
the number of the dominical letter is 7, or G. 

B, in the couplet, represents May, and is numbered 2 in the list 
of letters representing the days of the week. Then G is Sunday; 1, 
or A, is Monday; and 2, or B, is Tuesday. So, the first day of May is 
Tuesday. The 1st, the 8th, the 15th, the 22d, and the 29th are also 
Tuesday, and the 28th is Monday. 

solution. 
92 

23 7 less 4 is 3, and 3 is C, the dominical 

1 letter for January and February 

~~~ 1892. This would make January 

' 16th come on Saturday. 

16 and 4 rem. 
As 1892 was a leap year, we add to the years above centuries their 
one-fourth, plus 1. After February we add 2, in determining the 
dominical letter for the balance of the year. 

2. Find the day of the week that Columbus landed in the new 
world. On what day of the week was the Declaration of Independ- 
ence signed? The World's Fair closed October 31, 1893. What day 
was it? 

3. On what day were you born? On what day will the first of 
March, 1900, occur? 

Here is another method of finding the day of 
the week that will furnish you with a fine problem 
for explanation. 



150 THE CALENDAR. 

To tell the day of the week, first take the number 
represented by the last two figures of the number 
of the year, and add a quarter to this, disregarding 
the remaining fraction. Then add the number of the 
day of the month to the sum, and to this add the 
number standing for the month, taken from the series 
366,240,251,361, counting the first figure in the series 
as January, the second as February, the third as 
March, and so on. Divide the sum by 7, and the re- 
mainder will give the number of the day of the week ; 
and, when there is no remainder, the day will be Sat- 
urday. 

As an example, take March 19, 1890. Take 90, 
add 22, add 19, add 6. This gives 137, which 
divided by 7, leaves a remainder of 4,* which is the 
number of the day of the week, or Wednesday. 

You remember that it is always noon on the sun's 
meridian ; and you have probably taken a trip around 
the world, in your mind, keeping up with the sun, 
and found " everybody eating dinner as you passed." 
Perhaps you wondered how it happened, that it was 
Monday at noon all of the way around, but that, when 
you got to the starting point, it was Tuesday noon. 
This brings up the question of where the old day 

* The day before the one indicated by the "remainder" will be the 
day sought in January or February of a leap year. 



THE INTERNATIONAL DATE LINE, 151 

ends and the new begins. Sailors change their dates 
at the 180th meridian. If they are sailing westward 
they add one day to their reckoning, but deduct a 
day if they are going east. This happens in the 
Pacific Ocean. 

Settlements have been established on the islands 
of the Pacific by all nations of the world ; and they 
have carried with them the day of the week as it 
occurred at home, making no change for the change 
of longitude, so that people coming from eastern 
countries have established days different from those of 
people who have come from western countries. It is 
said that the days in these islands have not yet been 
made uniform, so that it is Monday at one place, and 
Sunday at another, on the same meridian. 

In American Notes and Queries, September 1, 
1888, page 215, is the following interesting item, 
under the heading of " The International Date Line:" 

"The international date line is a line at which dates 
must be made later by one day when crossing it from 
east to west, and earlier by one day when crossing it 
from west to east. This line passes just west of 
Behring Strait, west of St. Lawrence Island, west of 
Gore's Island, thence southwesterly between the 
Aleutian Islands and Asia. Some authorities place 
it east of the Behring Islands. It then passes south- 



152 THE CALENDAR. 

westerly some degrees east of Cape Lopatka, and the 
group of the Kurile Islands, thence just east of 
Japan, keeping west of Guadalupa and Marguerite's 
Islands, but east of Bonin, Liu Kiu Islands, and 
south east of Formosa. 

"The line then passes through Bashee Channel just 
north of Bashee Island, and enters the China Sea 
east of Hong Kong, then passes south just west of 
the Philippine Islands, but keeping east of Palawan 
Islands. It is here that it reaches its most western 
point, being about 116 degrees east longitude. It 
then takes a south easterly course through the Sulu 
Sea south of Mindanao Island and north of Gilolo 
Island. Thence it passes, nearly parallel to the 
equator and just north of it, to a point about 165 
degrees east longitude, just north of Schank's Is- 
land. From here it goes south easterly, leaving High 
Island, Gilbert's Archipelago, TaswelPs Island, and the 
DePeyster group on the north east, thence past the 
Navigator's or Samoan Islands, to longitude 168 west. 
It then turns south, keeping east of the Friendly, 
Tonga, Vasquez, and Curtis Islands, and west of the 
Society and Cook's Islands ; thence it continues, bear- 
ing a little to the west, so as to cross, according to 
some authorities, Chatham's Island, and thence to the 
south pole." 



IMPORTANCE OF PROBLEMS. 153 

We have now studied the earth, the moon, and 
the sun in their simplest relations to each other, and 
their most important points of interest to us. This 
work will be robbed of its greatest importance if 
you do not work out all of the problems given, 
which can be easily done by the assistance of your 
Tellurian. 

You will find in the "Appendix" some things that 
will interest you, and some definitions that you 
should study from time to time as you have need of 
them. 



APPENDIX. 



SOIMIIE FIG-TJBES. 



The earth's diameter is about 7,925^ miles at the 
equator. 

The moon's diameter is 2,160 miles. 

The sun's diameter is 852,584 miles. 

The moon's nearest point to the earth is 225,719 
miles. 

The moon's most distant point from the earth is 
251,947 miles. 

The earth's nearest point to the sun is 89,894,951 
miles. 

The earth's most distant point from the sun is 
92,965,489 miles. 

The moon travels in her orbit at the rate of 2,273 
miles per hour. 

The earth travels in her orbit at the rate of 65,533 
miles per hour. 

To get a better idea of the magnitude of these 

(154) 



DEFINITIONS. 155 

distances, remember that our fastest express trains 
do not average 60 miles per hour. See how long 
it would take to cross the sun's disc. 

It is 477,666 miles across the moon's orbit. This 
is 374,918 miles less than the sun's diameter. 

Apparent Rotation of the Heavens. — If on any- 
clear night you watch the heavens for a few hours, 
you will notice that the stars have changed their 
positions, not with reference to each other, for they 
present the same figures for centuries, but they seem 
to be crossing the heavens from east to west. Those 
that were near the horizon and east of the point of 
observation appear higher up in the heavens, while 
those west of the point of observation have disap- 
peared below the horizon. All of the stars seem to 
move from east to west, except those near the Pole 
Star, which describe a circle around it. This is called 
the Apparent Rotation of the Heavens. The rotation 
of the earth causes all points in the heavens to appear 
to be moving, while, in fact, they have not greatly 
changed their relative position for ages. 



156 



APPENDIX. 



The following figure will show why the revolu- 
tion of the earth causes a star to rise, ascend to the 
zenith, and disappear below the western horizon : 




The circle, of which O is the center, represents 
the earth, and B ; C, and D are points at which observ- 
ers, at the same moment, are watching the star at A- 
The direction from B to D is east, and from D to B 
is west, while the star A is directly over the head of 
the observer at C. The star will appear to be rising 
to the observer at B, and setting to the observer at 
D, and, in looking at it, they will look in the direction 
that the arrows point. As the earth rotates from B 
to C, the line AB will gradually take the direction 



DEFINITIONS. 157 

of AC; and, as the earth continues her rotation, it 
will carry the point B to the point D, and then the 
line AB will take the same direction as the line AD, 
and the star will appear to have moved from the 
eastern to the western horizon. 

Cardinal Points, — The four principal points of 
the compass, — North, Mast, South, and West. 

Circle. — A ring; the compass or circuit of any 
thing or place; a single curved line, every point of 
which is equidistant from a point within called its 
center. Polar Circles are the Arctic and Antarctic 
circles. Great Circles are those circles whose planes 
pass through the center of a sphere and divide it 
into two equal parts. 

Celestial Meridian. — Is the great circle that passes 
through the zenith and the poles of the heavens. Its 
plane will also pass through the poles and the center 
of the earth. I have called it the Noon Meridian and 
the Sun's Meridian. 

Celestial Sphere. — Is the vast, hollow expanse of 
the heavens. It appears to us like the inner surface of 
a great dome, and the stars look like gilded specks 
attached to it. 

Mcliptic. — The apparent path of the sun in the 
heavens for a year, — so called because an eclipse cannot 
take place unless the moon be in or near the ecliptic. 



158 APPENDIX. 

Equator. — The supposed or imaginary great circle 
which passes around the earth at an equal distance 
from both poles, and divides the earth into the North- 
ern and the Southern Hemispheres. 

Equinox. .—The time when the sun crosses the 
equinoctial line, and when all places on the earth's 
surface have days and nights of equal length. The 
Vernal Equinox occurs on the 20th of March,* at 
the moment when the sun crosses the equator. The 
celestial meridian that contains this point is the 
meridian from which astronomers reckon the location 
of the stars, the same as we reckon longitude from 
the meridian of Greenwich, The Autumnal Equinox 
occurs September 2 2d, when the sun again crosses the 
equator; but it is not used as a point from which 
to reckon locations. In reckoning from the Vernal 
Equinox, astronomers always reckon eastward, and 
completely around the circle. 

Hemisphere.— Half of a sphere. The sun shines 
on one-half of the earth's surface all of the time, and 
I have called this half the Day Hemisphere. The 

* The dates of the equinoxes and solstices may not be the same 
for all points on the surface of the earth, because of their difference in 
time. Suppose that the sun should cross the equator at the meridian 
of Greenwich at 2:30 o'clock a. m. on the 21st of March. Its time of 
crossing, for the United States, would be at some time before midnight 
on the 20th of March. The sun does not cross the equator at the same 
point, or at the same time each year. 



DEFINITIONS. 159 

half of the earth's surface that is in the shadow is 
the Night Hemisphere. 

Hour- Circles. — The twenty-four meridians repre- 
sented on the surface of the globe. They are fifteen 
degrees apart, or just one hour in time. Strictly 
speaking, hour-circles are meridians in the celestial 
sphere that are fifteen degrees apart, and located with 
reference to the celestial meridians. 

Meridians. — Great circles that pass through the 
poles of the earth or of the heavens. These lines 
are imaginary, and every point on the earth's surface 
may be considered to have a meridian passing through 
it. Only twenty-four of them are represented on the 
globe, and the meridian that passes through Green- 
wich is the one from which the longitude of all places 
on the earth is reckoned. 

Parallels. — Circles that cut the meridians at right 
angles. Only one of them is a great circle, the 
Equator; and, as with the meridians, every point on 
the surface of the earth may be considered to have 
a parallel passing through it. 

Hotation and Revolution. — Revolution is a broader 
term than rotation, and includes all that is meant by 
it, while rotation is more limited in its meaning. 
Rotate means to revolve around a point that is the 
center of the revolving body; and Revolve may mean 



160 APPENDIX. 

to rotate, or it may mean to go around a point that 
is not the center of the revolving body. 

Solstices. — Points in the earth's orbit where the 
sun has reached his most northern or southern lati- 
tude. There are two, — the Summer Solstice, which 
indicates the most northern latitude of the sun, and 
the Winter Solstice, which indicates his most southern 
latitude. 

Tropics. — The parallels of latitude in which the 
solstices occur. They are about 23^ degrees north 
and south of the equator and parallel to it. They 
mark the limits in which the sun moves in his yearly 
course. The one north of the equator is called the 
Tropic of Cancer, and the one south of the equator 
the Tropic of Capricorn. 

Zodiac. — An imaginary belt, about sixteen degrees 
wide (about eight degrees each side of the ecliptic), 
within which lie the planes of the orbits of all the 
planets. It is divided into twelve signs. (See 
Chapter IX.) 

A. LESSOR" OlsT THIS J±JLil&J±2<rJ±G. 

On the next page is given a cut of the Zodiac, 
together with the characters that represent the zodi- 
acal signs. The characters that represent the sun, 
moon, and the planets, are given, with the signs for 



THE ZODIAC. 



161 



conjunction, quadrature, and opposition. The moon is 
said to be in Apogee (ge means "earth") when she 
is at the most distant point in her orbit from the 
earth, and to be in Perigee when she is at the nearest 
point in her orbit to the earth. The earth is said to 
be in Aphelion when she is farthest from the sun, and 
in Perihelion when she is nearest the sun. . The signs 
for the ascending and descending nodes are given. 
Remember that node means the point where the moon 



crosses 



th 



e suns 



path. 



STANDARD TIME. 

The calculations of this Almanac are 
given in local time. In places w*here 
l ^rhat is now called standard time has 
been substituted for local time, our val- 
ues can be changed to standard time by- 
applying a correction found as follows: 
For any place east of one of the standard 
meridians, an4 taking that meridian's 
time, four minutes is to be subtracted 
for every degree of difference of longi- 
tude; and for anyplace ivest of the me- 
' ridian four minutes for each degree of 
difference is to be added. 



APPARENT RELATIVE POSITION 

OP THE EARTH. THE SUN, THE MOON", 

AND THE SIGNS OF THE ZODIAC. 




CHRONOLOGICAL CYCLES. 
Dorain. Letter . . G 

Epact .23 

Golden Number . 14 



Solar Cycle 27 

koman Indiction, 7 
Julian Period . . C607 



Zodiacal. — #& Aries — The Ram, Head and Face; £3 Taurus — Tbe Bull, Neck; 
tt Gemuii- The Twins, Arms; *f£ Cancer — The Crab, Breast ;S?$* Leo*— The Lion, Heart; 
•3f Virgo — The Virgin, Bowels; i*i Libra — The Balance, Reins; ^Scorpio — The Scor- 
pion, Secrets; & Sagittarius — The Bowman, Thighs; *& Capricornus — The Goat, 
Knees; A Aqua rius— The Waterman, Legs; ^ Pisces — The Fishes, Feet. 

j Characters. — 0, The Sun; $, Mercury; 9, Ve"nus; ©, The Earth; <[, The Moon; 
.£, farthest north; v, farthest south; tf, Mars; %, Jupiter; f? , Saturn; &, Uranus; t£, 
Neptune; (5, Conjunction; O, Quadrature, 90° from 0; £, Opposition, 180° from©'; Apogee, 
far from©; Perigee, near 0; Aphelion, far from©; Perihelion, near©; ft, Ascending 
flode; Q, Descending Node. r ' 

. Mercury^) will be evening star about February 25, June 23, and October 19; and morn- 
ing star about April 10, August 8, and November 27. 

Jjenus (9) will be evening star till February 15; then morning star till November 30,: 
&ng then evening star again the rest of the year. 

JupiUr (pi) will pe evening star till June 4; then mnruing star tUl December 22; and then 
evening star again the rest of the vear. 



162 



APPENDIX. 



The following table is to be used in the study 
of Chapter XIV: 



First Month. 



JANUARY-, 1894. 



31 Dayge 



MOON'S phases: 



NewM. 
First Q. 
Full M. 
Last Q. 



Halifax* 
D. h. m. 

6 10 53 A. 
14 7 55 A. 
21 10 57 M. 
28 37 A. 



JIOHtfSfe! 

D. h. si. 
610 13 A. 
14 7 15 A 
2110 17 M. 
28 11 57 M. 



Detroit. 
d. h. xnu 

3 835 A. 
14 6 37 A. 
21 939M 



St. Paul* 

i>. h. m. 
6 8 55 A, 

14 5 57 A. 
21 8 59M, 



28 I'l W M.I28 10 3SlM 



JJ* w * Miscellaneous Phenomena. \q^{ 



CALENDAR 

Por Northern N. E. 
and N.Y.; Upper 
Michigan, W i e., 
and Minn*; No. 
.Dakota; Montana 
and Washington.' 



San 

rises . 
h. n*. 



Sun 
sets. 
h. m. 



Moon 

rises. 
h. m. 



CALENDAR 

For Macsac-husetta: 
So. N. H. andVt.; 
Cent.' N.Y.; Lowet 
Mich., Wis. .and 
Minn. j 3o. Dak.; 
Idaho and Oreg'n. 



Sun 
rises. 
b. m. 



Sun 
8ets. 
h. m. 



Moon 
rises. 
h. m. 



Mo 
Tu 
We 
Th 

Fri 
Sat 



Circumcision. Slave trade'abol. 1808. 
9 Q. Dr. Ure d. 1S57. Snow. 

d <f d . Bat. Princeton. 1777. 
Bombardment of Paris, 1871. Cold. 
c5 § C ; d in apog. Blustering, v 
Epiphany. Iiime. D'Arbtey &* 1840.' 



7 41 
7 41 
7 41 
7 41 
7 41 
7 41 



2.42 

3 50 

4 56 
6 

6 59 

sets 



30 

30 

80 

30 

30K 

30 



2 35 

3 40 

4 44 

5 46 

6 44 

sets 



1) 1st Sunday after Epiphany. Yenua in Aquarius* 8h. 52m. Day's length. 9h. 15m. 



Su 

8^1o 
Tu 
101 We 



TH 
Fri 

Sat 



Ji^ 6. The French in Mexico, '62. 
Ijip Eli Whitney d . 1825 . . Clear 
Conn, adopted constitution, 1788. 
6 9 C ; ? gr. brilliancy. and cold. 
§ in aphel. F. Sect Key d. 1843. 
Terrible Dakota blizzard, 1888. 
d Q. . Salm. P. Chase b. 1808: 



41 

*0 

40 
40 

m 

7 38 



4 50 

5 56 

7 4 

8 12 

9 21 

10 30 

11 40 



5 3 

6 7 

7 12 

8 18 

9 24 

10 30 

11 37 



2y 2d Sunday after Epiphany. 



Mara in Scorpioi 9h. 4m. Day '^ length. 9h.24m. 



[Su 
Mo 
Tu. 
We 
Th 
Fri 
Sat 



J 14; Q^0. Car. Manning d.'92. 
^ stat. Dr. Parr b. 1747. 
d 1/. d . Gen. Hasen d. 1887. 
d^tf . Geo. Bancroft d. 1891. 
German empire proclaimed, 1371. 
Gen. Zolllkoffer kilied, 1862. 
C in perig. King Kal&kaua d. 1891. 



W9» 


17. 38 


4 42 


morn 


9 


7 28 


4 52 


*f 


7 37 


4 43 


52 


10 


7 27 


4 53 


4RP 


7 36 


4 44 


2 10 


10 


7 27 


4 54 


£3 


7 36 


4 45 


3 32 


10 


7 26 


4 55 


£3 


7 35 


4 47 


4 54 


11 


7 25 


4 56 


tf 


7 35 


4 48 


6 9 


11 


7 25 


4 58 


t* 


7 34 


4 49 


7'13 


11 


7 24 


4 59 



morn 
47 

2 2 

3 21 

4 40 

5 54 

6 58 



3) Septuagesima Sunday. 



Jupiter in Aries. 9h. 17m. Day's length. 9h. 37m. 



Su \0jj£k 21. Geo. D. Prentice d. 1870. 
Mo \3§/ Byron b. 1788. '' Snow- 

Til 9 stat. Gustave Dore d. 1883. 
We Rev. Charles Kingsley d. 1875. storm, 
Th Conversion of St. Paul. 
Fri rf 13 ; C £3- Dr. Jehner d. 1823. 
Sat dh C • Erap. William II. b. 1859. 



»€£ 


7 33 


4 50 


' rises 


12 


7 23 


5 


«H§£ 


7 32 


4 52 


6 15 


12 


7 23 


5 I 


£# 


7 31 


4 53 


7 38 


15 


7 22 


5 3f 


tf* 


7 30 


4 55 


8 57 


12 


7 21 


5 4 


8r 


7 29 


4 56 


10 9 


J3 


7 21 


5 5 


& 


7 28 


4 58 


11 20 


113 


7 20 


5 6 


if 


7 27 


4 59 


morn 


13 


7 19 


5 8 



rises 

6 23 

7 43 

8 57 
10 
11 16 
morn 



4) Sexagesima Sunday. 



Saturn in Virgo*. 9h. 36m. Day's length. 9h. 51m. 



Su 
Mo 
Tu 
We 



28. (5S<[. Stanley b. 1841. 

£ SO sup. * Cold. 

$ gr. hel. lat. S. Osceola d. 1838. 
d cf <l • Rev. C. «. Spurgeon d. £892. 



A 


7 26 


5 1 


29 


13 


7 18 


5 9 


A 


7 25 


5 2 


1 89 


13 


7 17 


5 10 


me 


7 24 


5 4 


2 48 


14 


7 17 


5 12 


HE 


7 23 


5 5 


3 53 


14 


7 15 


5 13 



23 

1 30 

2 36 

3 39 



PROBLEMS. 163 

IMIOIDIEILi LESSOIST OlST CHAPTEE X1I"V\ 

Q. At what point on the earth's surface will the 
attraction of the sun or of the moon be the strongest? 

A. If a line be drawn through the center of the 
earth and the center of the sun or of the moon, the 
point will be found in this line and at the surface of 
the earth. 

Q. Are the tides at this point higher than else- 
where on the same side of the earth? 

A. If the surface of the earth were an unbroken 
expanse of water, they would be higher at some dis- 
tance east of this point, and the movement of the 
tides would be quite different from what it is now. 
As it is, the coast lines have a disturbing influence 
on the tides, not only retarding their movements, but 
changing their direction and height. 

Q. What is the height of the tides in mid-ocean ? 

A. Perhaps less than two feet. There the height 
of the tides is the result of the attraction of the sun, 
or of the moon, or both, undisturbed by other influ- 
ences. 

Q. Why is not the height of tides the same at 
all places ? If the cause is constant, why is not the 
height uniform? 

A. The length and outline of seacoasts are the 
prime cause of their variation. If the shape of the 



164 APPENDIX. 

coast is such as to force the tide into a corner, its 
height will be greatly increased, as is the case in 
the Bay of Fundy. While the cause of the tides is 
constant, it does not act with equal force at all times 
during the month, the reason for which is evident. 

Q. Do tides travel with the same rate of speed 
all over the surface of the dearth? 

A. The extent and the depth of the bodies of 
water where tides are formed modify the rate at 
which they travel around the earth. Since North 
and South America extend almost from pole to pole, 
they act as an effectual barrier to the tides formed 
in the Atlantic Ocean. The tides beginning with 
the western coast of the Americas travel northwest 
across the Pacific at the rate of about 850 miles ail 
hour. The tidal wave in the shallow waters of 
Oceania travels at the rate of from 400 to 600 miles 
an hour. 

Q. Can the time at which the tides will reach any 
given point be reckoned? 

A. Yes; the tides depend upon conditions that 
are constant, so far as any location is concerned ; but 
different locations are surrounded by different con- 
ditions. 

Q. How does it happen that tides occur at oppo- 
site points on the earth's surface? 



THE TIDES. 165 

A. This is a different question. By assuming 
that the theory given on page 112 is correct, it is easy 
to see that the attraction of the moon would make 
a tidal wave on the portion of the earth's surface 
that is toward the moon. Tn the same way the solid 
portions of the earth are attracted by the moon, and 
this attraction would, probably, lessen the force of 
gravity on the opposite side of the earth from the 
moon. Now, water is slightly compressible, and, 
where there is great depth, it exerts an enormous 
pressure on the lower strata, so that they are more 
dense than the upper. If this pressure is relieved 
the whole body will be less dense, and will occupy 
more room. This would produce a wave unless the 
force of gravity were uniformly lessened all over the 
earth's surface, which is contrary to the theory. 

Q. Are there other theories for the causes of tides ? 

A. Yes. Perhaps you will find one in your Phys- 
ical Geography, or Encyclopaedia. Look it up care- 
fully. 

Q. What is meant by the " moon's node " ? 

A. It is the point in the moon's orbit where the 
moon's path cuts the ecliptic. The point where the 
moon passes from the southern portion of the ecliptic 
to the northern portion is called the ascending node. 
The opposite node is called the descending node. 



166 APPENDIX, 

Q. Can you tell whether the moon is north or 
south of the ecliptic? 

A. Yes; the convex side of the moon's crescent is 
always toward the ecliptic, — that is, toward the sun. 
Look at the old moon at 3 o'clock in the morning, 
and keep the above in mind; you will be surprised. 

Q. Why does the moon appear to be so much 
farther north at some times than she does at others ? 

A. Because we compare her position with the 
horizon. She follows about the same path in the 
heavens, from month to month, during the year. She 
never gets more than about five* degrees further north 
or five degrees further south than the sun does. So it 
must be our relative position that changes from time 
to time as the observations are made. By the earth's 
rotation points on the equator are carried around a 
circle something less than 25,000 miles in circumfer- 
ence. This circle is more or less inclined to the 
ecliptic, according to the time of the year that the 
observations are being made; and viewing the sun 
and the moon from different points has a wonderful 
effect upon their apparent positions. The experiments 
with the Tellurian for finding the apparent direction 
of the sun for different times of the day and of the 
year, can be made for finding the apparent direction 

of the moon. 
* 5° 8' 40" 



THE ECLIPTIC. 1C7 

Q. How can the ecliptic be located in the heavens? 

A. By learning the location of the planets. This 
can be done by studying the moon's movements as 
directed on page 122. The planets are near the eclip- 
tic, and a line passing through them will indicate 
nearly the sun's and the moon's path in the heavens. 
You can see that the position of the moon at mid- 
night on a midwinter day would be almost the same 
as that of the sun at noon on midsummer's day. 



TROPIC op 



CANCER 




THE ANALEMMA. 



(168) 



THE J^m'-A.Tj-Bll&l&J^. 

The foregoing figure is a representation of the 
Analemma as shown on the Tellurian. AB is a 
meridian, and the figures along this meridian indicate 
degrees of latitude. CD is a section of the equator. 
Various other parts of the figure are named in the cut. 

Q. For what is the analemma used? 

A. The analemma is used to show the latitude at 
which a line drawn through the centers of the sun 
and the earth would fall upon the earth's surface for 
any day of the year. This line would represent the 
direct rays of the sun. 

Q. Can we truly say that this is the latitude of 
the sun ? 

A. It amounts to the same thing, but the sun is 
not spoken of as having latitude. The term "declina- 
tion" is used in its stead, meaning distance in degrees 
north or south of the celestial equator. 

Q. Are, then, the latitude of the direct rays of the 
sun and the sun's declination the same? 

A. Yes. 

Q. The declination of the sun on the 26th of 

(169) 



1/0 APPENDIX". 

February is about the same as on the 15 th of October. 
Why is it not so warm, in northern latitudes, on the 
former date as on the latter? 

A. Each acre of ground in the same latitude 
and having the same slope receives the same amount 
of heat, but it does not produce the same effect; for, 
before October 15th, the earth has been receiving the 
heat of a summer's sun, while prior to February 26th, 
the earth has been storing up cold in ice-locked rivers 
and lakes, and snowclad hills and valleys. Much heat 
must be absorbed in overcoming this vast amount of 
cold; so the winter's cold is not all chased away until 
the sun has crossed the equator, which does not occur 
until the latter part of March. 

Q. What else can we learn from the analemma? 

A. We can more readily see the distance in lati- 
tude passed over by the direct rays of the sun in any 
month of the year, and compare this with the distance 
passed over in any other month. (Compare June and 
September. ) 

Q. Why is this distance greater for some months 
than it is for others ? 

A. Because the rate of the earth's movement in 
her orbit is not uniform, the form of her orbit being 
that of an ellipse; and, in the case of June and Decem- 
ber, the sun seems to turn in his course north or south 



EQUATION OF TIME. 171 

and go in the opposite direction, so that the distance 
in latitude passed through in these months is much 
less than it is for any of the other months. A close 
observation of the analemma at these points will make 
more clear the meaning of the word " Solstice." (See 
page 63.) 

Q. What is meant by the "equation of time "? 

A. One of the principal means that we first had 
of reckoning time was by observing the sun, calling it 
noon when the sun was on our meridian, the highest 
point in the heavens for the day. Then came the 
division from noon to noon into hours and minutes, 
and the attempt to get some mechanical device that 
would record them as they occurred. This brought 
into existence the clock. It was found that the sun 
did not reach the same meridian at exactly the same 
time each day, and that the time as indicated by the 
sun-dial and mean solar time and that kept by good 
timepieces did not agree, except at four different dates 
during the year. The greatest difference occurs on 
the 2d of November, and about the 11th of February. 
On the 2d of November the sun is 16 minutes and 20 
seconds fast, and, on the 10th and 11th of February, 
14 minutes and 27 seconds slow. 

This difference is called the equation of time, and 
in some almanacs it is given for each day of the year. 



172 



APPENDIX, 



MOON'S PEASES, 



© New Moon,,. 

9 First Quarter,. .. 

© Fxtll Moon ... 

C Last Quarter* ... 



Day*. 



2£2TG&1C£L Z7ENT8. 



Sun 
Slow. 

B*. 8. 



BOSTON. 



D. H. M, 

6 6 1 Eve. 

13 o 69 Mor. 

19 9 32 Eve. 

27 .7 44 Mor. 



H. M 



Stm 
sets. 
a. m. 



Moon, 

11808. 



PITT3B3BGH. NEW OELEANa 



D. H. M. 

6 4 25 Eve. 

13 6 23 Mor, 

19 8 66 Eve. 

27 7 8 Mot. 



Sin 
rises. 

H.M. 



Sun 
sots.. 

H.M. 



ilooa 
rises. 

H. M 



D. H. M. 

6 3 45 Eve. 

IB 4 43 Moi. 

19 8 16 Eve. 

27 6 28 Mor. 



Sua 
rise* 

H.M. 



Sun 
sets. 

H.M. 



Moon 
rises. 

H. M 



Sir Edward Coke fo.4552 
Rich. H. DaDa died,1879 
F. W, Robertson b., 1816 



13 51 
13 59 
14. 6 



7 14 

7^13 
7 12 



5 14 
5 16 
5 17 



4 38 
631 
6 17 



7 10 
7 9 
7 8 



5 18 

6 19 

5 20 



4 31 

5 24 

6 10 



6 51 
6 50 
6 49 



5 38 
5 38 
5 39 



3 54 

4 46 
535 



(5.) aUI^UAQESIMA— SHSOVB SUNDAY. Luko IS. 



Day's Length, (Pitts.) 10 h. 14 m. 



4 


S 


6 


Mo 


6 


Tu 


7 


We 


8 


Th 


9 


Fi-i 


10 


Sa 



Battle Moorefieldi 1864 
Mass. rat. Constitu., 1788 
Ft. Henry captured,1862 
Pitt's Cabinet diss.. 1801 
New Prussian eonst.1847 
Gen. Hancock- died, 1886 
Reverdy Johnson d. 1876 



14 11 
14 15 
14 19 
14 22 
14 26 
14 26 
14 27 



7 11 
7 10 
7 9 



6 18 

5 19 

6 21 
5 22 
5 23 
5 25 
5 26 



6.54 

SETS 

6 10 

7 16 

8 23 

9 30 



5 21 
5 22 
5 24 
5 26 
5 26 
5 27 



6 48 



6.15 
7 19 
825 
9 



10 39 7 629 10 38 6 44 5 45 10 27 



6 49 
6 48 
6 47 
6 47 
6 46 
6 45 



5 40 
5 41 
5 42 
5 42 
5 43 
5 44 



6 17 

SETS 

6 34 

7 31 
829 
927 



<S f ) 1st SUNDAY m LENT. 



Matt. 4. 



gay's Length, (Pitts.) 10. h. 31 m. 



11 


8 


12 


Mo 


13 


Tu 


14 


We 


15 


Th 


16 


Fri 


17 


Sa 



Daniel Boone born, 1735 
O'Brien & Dillon sur./91 
Wm. and Mary proc.1689 
Gen. Sherman died, 1891 
Loais XV. born, 1710 
St, Independence lost '53 
Thiers eleeted Pres.^871 



V 


14 27 


7 2 


5 "27 


M60 


6 69 


530 


11 47 


644 


5 46 


'! 


14 26 


7 1 


5 29 


MOR 


6 57 


5 32 


MOB. 


8 43 


5 47 


14 24 


6 69 


5 30 


1 5 


6 56 


5 33 


1 


642 


5 47 


H 


14 22 


6 58 


5 31 


222 


665 


534 


2 16 


641 


548 


H 


14 19 


6 67 


5 32 


336 


6 54 


5 35 


3 29 


6 40 


5 49 


n 


14 15 


6 66 


■6 34 


4 43 


6 52 


5 36 


4 36 


6 39 


550 


a 


14 10 


6 54 


535 


6 39 


6 51 


537 


6 33 


6 38 


5 51 



11 29 

MOR. 

035 
143 

252 
3^8 

458 



(7.) 2d SUNDAY IN LENT. 



Matt. 15. 



Day's Length, (Pitts.) 10 fc. 43 m. 



18 


8 


19 


Mo 


20 


Tu 


21 


We 


22' 


Th 


23 


Fri 


24 


Sa 



Charleston captured*. '65 
Aaron Burr arrest., 1807 
David Garrick born,1716 
Wash. Mob, dedicat.1885 
David n.,Scotl'd,d.,1721 
Hornet capt. Penguin^ 
Revolution in Mex., 1821 



23 


14 5 


6 93 


5 36 


622 


650 


5 38 


6 17 


6 37 


5 51 


<S 


13 59 


6 51 


537 


RISE. 


6 49 


5 39 


RISE. 


636 


5 52 


m 


13 52 


6 60 


5 39 


6 30 


6 47 


5 40 


633 


6 36 


5 53 




13 46 


6 48 


5 40 


7 43 


6 46 


5 42 


7 44 


635 


564 


ftp 


13 37 


6 47 


5 41 


8 55 


6 44 


5 43 


855 


6 34 


554 


lip 


13 29 


6 46 


5 43 


10 5 


6 43 


5 44 


10 3 


633 


555 


£t 


13 19 


644 


5 44 


11 14 


6 41 


5 45 


1111 


632 


5 56 



5 49 

RISE. 

6 46 

7 48 
850 
9 51 

10 51 



(3.) 3d SUNDAY IN LSNT. 



Luke 11. 



Day's Length, (Pitts.) 11 h. 6 m. 



1st V. S. Bank cbart..l79l 
French Republic, 1848 
Tories defeat'oVN C1778 
Rachel born, 1820 



^v 


13 10 


6 42 


5 45 


Mon. 


6 40 


5 46 


MOR. 


6 31 


5 56 


-/-v 


13 


6 41 


5 46 


22 


6 38 


5 48 


17 


630 


667 


m 


12 49 


6 39 


5 47 


1 27 


6 37 


5 49 


1 21 


629 


558 


itf 


12 37 


6 38 


5 49 


228 


635 


550 


2 21 


628 


558 



11 50 

MOR. 

048 
1 45 



Above is a table for the month of February, 1894. 
The column in which the equation of time is given 
is marked "Sun Slow." 



THE AN A LEMMA. 173 

Q. Can this equation of time be determined by 
the Tellurian? 

A. Yes ; within a few seconds. Fix the movable 
meridian on your Tellurian so that it will be in the 
position of the dotted line in the cut of the analemma, 
on page 168, and notice that it touches February at 
about the 11th. Also notice that it crosses the scale 
of time between 14 and 15, which shows that the 
difference in time is between 14 and 15 minutes, and 
that it is on the side of the analemma that indicates 
that the sun is slow compared with the clock. 

Notice the column in your almanac that reads 
"Sun Fast" or "Sun Slow." 

FINIS. 



POLITICO-RELIEF MAPS, 

showing the contour and topography of a country, as well as the political 
divisions and other principal details. 

All teachers and students recognize the importance of studying the 
topography of the land as v ell as the political boundaries, location of physical 
features, such as lakes, rivers, etc. 

It has been difficult heretofore to pursue such studies without necessarily 
referring to one map for the political features, to another for the physical 
features, and to a third for the topography, or, possibly, to the imagination, or 
a crude and imperfect relief map mad^e by the teacher at odd moments. 
These Maps happily overcome all former difficulties, because they combine 
the relief features with all the features of the ordinary flat map, the names, 
etc., appear in print, the same as on any flat map. The most wonderful 
feature of these Maps is — How is it possible to have the printing so regular, 
so perfect, when the surface is so rough and uneven, representing, as it does, 
the appearance of the country? The substance is light; not including the 
frame that surrounds it, the weight will not exceed five or six ounces, and yet 
it is impossible to batter down the surface by striking it with a hammer. 

Being in a position to feel the pulse of the leading educators generally 
upon topics that pertain to their profession, and having realized that the 
time has come when relief maps must take the place of all flat maps, the 
publishers take great pleasure in announcing to their many friends and 
patrons that, after years of experimental work, and an outlay of many 
thousands of dollars, they have succeeded in producing the First Complete 
Set of PoIitico= Relief Maps; gaining for themselves the highest praise, for 
their sagacity and enterprise, from the leading educators of the w r orld. These 
Maps have been pronounced one of the marvels of the Nineteenth Century, 
by the most prominent Geographers and Scientists, and interest the teacher, 
the pupil and parent, and in every instance call forth expressions of surprise 
and astonishment from all. 

The complete set of seven Maps— consisting of North America, South 
America, Europe, Asia, Africa, United States, and The World (Mercator's 
Projection) — are each mounted in a beautiful carved Solid-Oak Frame, and 
enclosed in an elegant Antique-Oak Cabinet Case. 

Full particulars given, and illustrated circulars sent to any address. 

Central School Supply House, 

S. E. Cor. Monroe and Fifth Ave., - Chicago, 111. 



The Teachers'. 

Anatomical Aid. 



It is si series of lithographic plates, 25x42 inches in size, and complete 
manikins of the human bo iy — the head, the eye, the ear. the tooth, the 
lungs and heart, and ihe larynx; illustrating human anatomy and physiology, 
also showing the effects of alcoholic drinks and narcotics on the system. 

The Aid has been before the public for a number of years and has 
merited the highest praise, and stands pre-eminently superior in its line. 
The large sale it has enjoyed, and its use in the best schools bespeak for it 
the careful consideration of all who may be interested in apparatus of this 
'rind. The following is a list of the large sheets, with full-sized ill"- + ~at.ions, 
and what they teach: 

1. Title Page. 

2. Front View of Skeleton. 

3. Back View of Skeleton. 

4. The Muscular System. 

5. The Arteries and Veins. 

6. The Nervous System; The Five Senses; The Sympathetic System. 

7. The Formation and Circulation of Blood; The Oxygenation of Blood; 
Microscopic Details of Structure. 

8. The Stomach in Health. The Primary and Secondary Effects of Alcohol 
on the Mucous Membrane. 

9. The Stomach in Advanced State of Alcoholism; State in Delirium 
Tremens. Effect of Beer or Gin on the Kidneys. Gin or Hob-Nailed Liver. 

10. Alcoholic Effect on the Brain, the Heart, the Nerves, the Eyes, tho 
Arteries and Veins, the Liver and Skin. The Baneful Effects of Cigarette 
Smoking and its Destruction of Respiratory Organs; also Ulcerous and 
Cancerous Growth in the Larynx. 

By the aid of the manikins, the student will go through a process similar 
to dissection, and have the whole organism before him, with each in its proper 
place. Without seeing the apparatus, it would be difficult to comprehend 
how the interior of the body is exhibited, and how the organs may be taken 
out one after another, until all have been removed. 

The Case in which the apparatus is enclosed stands upright 4^1 inches, 
and is supported by an easel at an angle of 75 degrees. It is constructed of 
wail-seasoned ash, beautifully carved, making it both durable and artistic. 
When not in use, it can be closed up, thus protecting it from dust or other 
injury. The case holds the sheets flat and neat, and does not permit them to 
twist or roll. 

Correspondence solicited. Illustrated circulars and full particular^ giver 
on receipt of request. Address 

CENTRAL SCHOOL SUPPLY HOUSE, 

3. E, Cor. Monroe and Fifth Ave., Chicago, III. 



The. 



ppogpe^ive Reading and plumbei* j&ndij, 



BY 
MISS MARY E. BURT 



is placed before the educational public by the publishers, in the confident ^t?utji that teachers 
in every grade of school work will hail its appearance with happy enthusiasm. Believing with 
all our leading educators, that reading ranks first in importance among the educational stud- 
ies, they have spared neither care nor money to present, in this Study, a work in keeping 
with the great importance accorded this subject in the course of instruction given in our 
schools. 

THE ILLUSTRATIONS were selected from some of the most noted masters of the Old 
and New Worlds. Pen sketches were made from photographs of the originals, with slight 
modifications, to adapt the picture to the child's capacity, or to emphasize some particular 
feature. 

ART AND ILLUSTRATIONS— The art work alone cost thousands of dollars, and the 
publishers are receiving thanks and congratulations from teachers wherever the Study is 
shown for the progress they have made, 

SUPPLEMENTARY READING is taken up in three books, 6 by 10 inches; they are ele- 
gantly illustrated, the pictures affording ample opportunity to enlarge upon the lesson. 

ELEMENTARY NUMBER WORK— An urgent demand on the part of our primary 
teachers, and in aii courses of study for our common schools, induced the publishers to com- 
bine this course with the earlier lessons in reading. In doing so the inductive method of 
Grube, with such modifications as have been made in recent years by expert teachers, was 
followed. This complete course comprises forty pages, 10 by 14 inches in size, and provides 
both class drill and seat work. There are also several pages devoted to United States money 
and the operations of making change, etc. 

THE COLOR FOLIO— To meet the demand for color work in our schools the publishers 
have prepared a four-page folio, devoted entirely to the subject of color. The colors used are 
Prang's; the finest colors in scaled tones yet produced. 

TIME is illustrated by means of five lithographed figures, showing: (l) Natural Divis- 
ions of Time; (2) Causes Producing Such Divisions; (3) Comparative Time Throughout the 
World; (4) The Phases of the Moon; (5) Clock Dial with Movable Hands. 

THE AUTHOR— The publishers were fortunate in securing the services of Miss M^ry E. 
Burt to prepare and arrange the matter presented in its pages. She has made p lary 
instruction the chief labor and study of her life, and is recognized by educators as one of the 
best teachers of children in the country. 

THE CASE AND MOUNTING— The Main Study contains fifty large pages, 22x35 inches, 
mounted on heavy linen lined paper, including one page of geometrical forms. It is enclosed 
in an Antique Ash Cabinet Case, 36 inches high, and arranged so that when twenty-five lessons 
have been learned, the Main Study can be lifted out and reversed, when the succeeding les- 
sons can be presented as before. The Case stands at an angle of about 75 degrees. W T hen 
not in use, can be closed and locked, thus protecting it in every way. 

Write for illustrated circulars and full particulars to 

Central School Supply House, 

S. E. Cor. Monroe and Fifth Ave., Chicago. 



